RASMOL(1) General Commands Manual RASMOL(1)
NAME
rasmol - Molecular Graphics Visualisation Tool v2.7.5
SYNOPSIS
rasmol [-nodiplay] [[-format ] filename] [-script scriptfile]
FORMATS
-pdb Protein Data Bank
-mdl MDL's MOL File Format
-mol2 Tripos' Sybyl MOL2 Format
-xyz MSC's XYZ (XMol) Format
-mopac MOPAC Input or Output File Format
-alchemy Alchemy File Format
-charmm CHARMm File Format
-cif IUCr CIF or CIF File Format
NOTICES
This software has been created from several sources. Much of the code is from RasMol 2.6, as created by Roger Sayle. The torsion angle
code, new POVRAY3 code and other features are derived from the RasMol2.6x1 revisions by Arne Mueller. The Ramachandran printer plot code
was derived from fisipl created by Frances C. Bernstein. See the Protein Data Bank program tape.
The code to display multiple molecules and to allow bond rotation is derived in large part from the UCB mods by Gary Grossman and Marco
Molinaro, included with permission of Eileen Lewis of the ModularCHEM Consortium.
The CIF modifications make use of a library based in part on CBFlib by Paul J. Ellis and Herbert J. Bernstein. Parts of CBFlib is loosely
based on the CIFPARSE software package from the NDB at Rutgers university. Please type the RasMol commands help copying, help general,
help IUCR, help CBFlib,
and help CIFPARSE for applicable notices. Please type help copyright for copyright notices. If you use RasMol V2.6 or an earlier ver-
sion, type the RasMol command help oldnotice.
COPYING
This version is based directly on RasMol version 2.7.4.2, on RasMol verion 2.7.4.2, on RasMol version 2.7.4, on RasMol version 2.7.3.1, on
RasMol version 2.7.3, on RasMol version 2.7.2.1.1, Rasmol version 2.7.2, RasMol version 2.7.1.1 and RasTop version 1.3 and indirectly on
the RasMol 2.5-ucb and 2.6-ucb versions and version 2.6_CIF.2, RasMol 2.6x1 and RasMol_2.6.4.
RasMol 2.7.5 may be distributed under the terms of the GNU General Public License (the GPL), see
http://www.gnu.org/licenses/gpl.txt
or the file GPL or type the command help GPL
or RasMol 2.7.5 may be distributed under the RASMOL license. See the file NOTICE or type the command help RASLIC
GPL
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its
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When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure
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TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be dis-
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NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
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END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to
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To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most
effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the
full notice is found.
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software; you can redistribute it and/or modify
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This program is distributed in the hope that it will be useful,
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If the program is interactive, make it output a short notice like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the
commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever
suits your program.
You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the
program, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to
do, use the GNU Library General Public License instead of this License.
RASLIC If you do not use the GPL, the following license terms apply:
RasMol License
Even though the authors of the various documents and software found here have made a good faith effort to ensure that the documents
are correct and that the software performs according to its documentation, and we would greatly appreciate hearing of any problems
you may encounter, the programs and documents any files created by the programs are provided **AS IS** without any warranty as to
correctness, merchantability or fitness for any particular or general use.
THE RESPONSIBILITY FOR ANY ADVERSE CONSEQUENCES FROM THE USE OF PROGRAMS OR DOCUMENTS OR ANY FILE OR FILES CREATED BY USE OF THE
PROGRAMS OR DOCUMENTS LIES SOLELY WITH THE USERS OF THE PROGRAMS OR DOCUMENTS OR FILE OR FILES AND NOT WITH AUTHORS OF THE PROGRAMS
OR DOCUMENTS.
Subject to your acceptance of the conditions stated above, and your respect for the terms and conditions stated in the notices
below, if you are not going to make any modifications or create derived works, you are given permission to freely copy and distrib-
ute this package, provided you do the following:
1. Either include the complete documentation, especially the file NOTICE, with what you distribute or provide a clear indication
where people can get a copy of the documentation; and
2. Please give credit where credit is due citing the version and original authors properly; and
3. Please do not give anyone the impression that the original authors are providing a warranty of any kind.
If you would like to use major pieces of RasMol in some other program, make modifications to RasMol, or in some other way make what
a lawyer would call a "derived work", you are not only permitted to do so, you are encouraged to do so. In addition to the things we
discussed above, please do the following:
4. Please explain in your documentation how what you did differs from this version of RasMol; and
5. Please make your modified source code available.
This version of RasMol is _not_ in the public domain, but it is given freely to the community in the hopes of advancing science. If
you make changes, please make them in a responsible manner, and please offer us the opportunity to include those changes in future
versions of RasMol.
General Notice
The following notice applies to this work as a whole and to the works included within it:
* Creative endeavors depend on the lively exchange of ideas. There are laws and customs which establish rights and responsibilities
for authors and the users of what authors create. This notice is not intended to prevent you from using the software and documents
in this package, but to ensure that there are no misunderstandings about terms and conditions of such use.
* Please read the following notice carefully. If you do not understand any portion of this notice, please seek appropriate profes-
sional legal advice before making use of the software and documents included in this software package. In addition to whatever other
steps you may be obliged to take to respect the intellectual property rights of the various parties involved, if you do make use of
the software and documents in this package, please give credit where credit is due by citing this package, its authors and the URL
or other source from which you obtained it, or equivalent primary references in the literature with the same authors.
* Some of the software and documents included within this software package are the intellectual property of various parties, and
placement in this package does not in any way imply that any such rights have in any way been waived or diminished.
* With respect to any software or documents for which a copyright exists, ALL RIGHTS ARE RESERVED TO THE OWNERS OF SUCH COPYRIGHT.
* Even though the authors of the various documents and software found here have made a good faith effort to ensure that the docu-
ments are correct and that the software performs according to its documentation, and we would greatly appreciate hearing of any
problems you may encounter, the programs and documents and any files created by the programs are provided **AS IS** without any war-
ranty as to correctness, merchantability or fitness for any particular or general use.
* THE RESPONSIBILITY FOR ANY ADVERSE CONSEQUENCES FROM THE USE OF PROGRAMS OR DOCUMENTS OR ANY FILE OR FILES CREATED BY USE OF THE
PROGRAMS OR DOCUMENTS LIES SOLELY WITH THE USERS OF THE PROGRAMS OR DOCUMENTS OR FILE OR FILES AND NOT WITH AUTHORS OF THE PROGRAMS
OR DOCUMENTS.
See the files GPL and RASLIC for two alternate ways to license this package.
RasMol V2.6 Notice
The following notice applies to RasMol V 2.6 and older RasMol versions.
Information in this document is subject to change without notice and does not represent a commitment on the part of the supplier.
This package is sold/distributed subject to the condition that it shall not, by way of trade or otherwise, be lent, re-sold, hired
out or otherwise circulated without the supplier's prior consent, in any form of packaging or cover other than that in which it was
produced. No part of this manual or accompanying software may be reproduced, stored in a retrieval system on optical or magnetic
disk, tape or any other medium, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or oth-
erwise for any purpose other than the purchaser's personal use.
This product is not to be used in the planning, construction, maintenance, operation or use of any nuclear facility nor the flight,
navigation or communication of aircraft or ground support equipment. The author shall not be liable, in whole or in part, for any
claims or damages arising from such use, including death, bankruptcy or outbreak of war.
IUCR Policy
The IUCr Policy for the Protection and the Promotion of the STAR File and CIF Standards for Exchanging and Archiving Electronic
Data.
Overview
The Crystallographic Information File (CIF)[1] is a standard for information interchange promulgated by the International Union of
Crystallography (IUCr). CIF (Hall, Allen & Brown, 1991) is the recommended method for submitting publications to Acta Crystallo-
graphica Section C and reports of crystal structure determinations to other sections of Acta Crystallographica and many other jour-
nals. The syntax of a CIF is a subset of the more general STAR File[2] format. The CIF and STAR File approaches are used increas-
ingly in the structural sciences for data exchange and archiving, and are having a significant influence on these activities in
other fields.
Statement of intent
The IUCr's interest in the STAR File is as a general data interchange standard for science, and its interest in the CIF, a confor-
mant derivative of the STAR File, is as a concise data exchange and archival standard for crystallography and structural science.
Protection of the standards
To protect the STAR File and the CIF as standards for interchanging and archiving electronic data, the IUCr, on behalf of the scien-
tific community,
* holds the copyrights on the standards themselves,
* owns the associated trademarks and service marks, and
* holds a patent on the STAR File.
These intellectual property rights relate solely to the interchange formats, not to the data contained therein, nor to the software
used in the generation, access or manipulation of the data.
Promotion of the standards
The sole requirement that the IUCr, in its protective role, imposes on software purporting to process STAR File or CIF data is that
the following conditions be met prior to sale or distribution.
* Software claiming to read files written to either the STAR File or the CIF standard must be able to extract the pertinent data
from a file conformant to the STAR File syntax, or the CIF syntax, respectively.
* Software claiming to write files in either the STAR File, or the CIF, standard must produce files that are conformant to the
STAR File syntax, or the CIF syntax, respectively.
* Software claiming to read definitions from a specific data dictionary approved by the IUCr must be able to extract any perti-
nent definition which is conformant to the dictionary definition language (DDL)[3] associated with that dictionary.
The IUCr, through its Committee on CIF Standards, will assist any developer to verify that software meets these conformance condi-
tions.
Glossary of terms
[1] CIF:
is a data file conformant to the file syntax defined at http://www.iucr.org/iucr-top/cif/spec/index.html
[2] STAR File:
is a data file conformant to the file syntax defined at http://www.iucr.org/iucr-top/cif/spec/star/index.html
[3] DDL:
is a language used in a data dictionary to define data items in terms of "attributes". Dictionaries currently approved by the IUCr,
and the DDL versions used to construct these dictionaries, are listed at http://www.iucr.org/iucr-top/cif/spec/ddl/index.html
Last modified: 30 September 2000
IUCr Policy Copyright (C) 2000 International Union of Crystallography
CBFLIB The following Disclaimer Notice applies to CBFlib V0.1, from which this code in part is derived.
* The items furnished herewith were developed under the sponsorship of the U.S. Government. Neither the U.S., nor the U.S. D.O.E.,
nor the Leland Stanford Junior University, nor their employees, makes any warranty, express or implied, or assumes any liability or
responsibility for accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents
that its use will not infringe privately-owned rights. Mention of any product, its manufacturer, or suppliers shall not, nor is it
intended to, imply approval, disapproval, or fitness for any particular use. The U.S. and the University at all times retain the
right to use and disseminate the furnished items for any purpose whatsoever.
Notice 91 02 01
CIFPARSE
Portions of this software are loosely based on the CIFPARSE software package from the NDB at Rutgers University. See
http://ndbserver.rutgers.edu/NDB/mmcif/software
CIFPARSE is part of the NDBQUERY application, a program component of the Nucleic Acid Database Project [ H. M. Berman, W. K. Olson,
D. L. Beveridge, J. K. Westbrook, A. Gelbin, T. Demeny, S. H. Shieh, A. R. Srinivasan, and B. Schneider. (1992). The Nucleic Acid
Database: A Comprehensive Relational Database of Three-Dimensional Structures of Nucleic Acids. Biophys J., 63, 751-759.], whose
cooperation is gratefully acknowledged, especially in the form of design concepts created by J. Westbrook.
Please be aware of the following notice in the CIFPARSE API:
This software is provided WITHOUT WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR ANY OTHER WARRANTY, EXPRESS OR
IMPLIED. RUTGERS MAKE NO REPRESENTATION OR WARRANTY THAT THE SOFTWARE WILL NOT INFRINGE ANY PATENT, COPYRIGHT OR OTHER PROPRIETARY
RIGHT.
DESCRIPTION
RasMol is a molecular graphics program intended for the visualisation of proteins, nucleic acids and small molecules. The program is aimed
at display, teaching and generation of publication quality images. RasMol runs on wide range of architectures and operating systems
including Microsoft Windows, Apple Macintosh, UNIX and VMS systems. UNIX and VMS versions require an 8, 24 or 32 bit colour X Windows dis-
play (X11R4 or later). The X Windows version of RasMol provides optional support for a hardware dials box and accelerated shared memory
communication (via the XInput and MIT-SHM extensions) if available on the current X Server.
The program reads in a molecule coordinate file and interactively displays the molecule on the screen in a variety of colour schemes and
molecule representations. Currently available representations include depth-cued wireframes, 'Dreiding' sticks, spacefilling (CPK) spheres,
ball and stick, solid and strand biomolecular ribbons, atom labels and dot surfaces.
Up to 5 molecules may be loaded and displayed at once. Any one or all of
the molecules may be rotated and translated.
The RasMol help facility can be accessed by typing "help <topic>" or "help <topic> <subtopic>" from the command line. A complete list of
RasMol commands may be displayed by typing "help commands". A single question mark may also be used to abbreviate the keyword "help".
Please type "help notices" for important notices.
COMMANDS
RasMol allows the execution of interactive commands typed at the RasMol> prompt in the terminal window. Each command must be given on a
separate line. Keywords are case insensitive and may be entered in either upper or lower case letters. All whitespace characters are
ignored except to separate keywords and their arguments.
All commands may be prefixed by a parenthesized atom expression to temporarily select certain atoms just for the execution of that one com-
mand. After execution of the command, the previous selection is restored except for the commands select , restrict and script.
The commands/keywords currently recognised by RasMol are given below.
Backbone
The RasMol backbone command permits the representation of a polypeptide backbone as a series of bonds connecting the adjacent alpha
carbons of each amino acid in a chain. The display of these backbone 'bonds' is turned on and off by the command parameter in the
same way as with the wireframe command. The command backbone off turns off the selected 'bonds', and backbone on or with a number
turns them on. The number can be used to specify the cylinder radius of the representation in either Angstrom or RasMol units. A
parameter value of 500 (2.0 Angstroms) or above results in a "Parameter value too large" error. Backbone objects may be coloured
using the RasMol colour backbone command.
The reserved word backbone is also used as a predefined set ("help sets") and as a parameter to the set hbond and set ssbond com-
mands. The RasMol command trace renders a smoothed backbone, in contrast to backbone which connects alpha carbons with straight
lines.
The backbone may be displayed with dashed lines by use of the backbone dash command.
Background
The RasMol background command is used to set the colour of the "canvas" background. The colour may be given as either a colour name
or a comma separated triple of Red, Green and Blue (RGB) components enclosed in square brackets. Typing the command help colours
will give a list of the predefined colour names recognised by RasMol. When running under X Windows, RasMol also recognises colours
in the X server's colour name database.
The background command is synonymous with the RasMol set background command.
Bond The RasMol command bond <number> <number> + adds the designated bond to the drawing, increasing the bond order if the bond already
exists. The command bond <number> <number> pick selects the two atoms specified by the atom serial numbers as the two ends of a
bond around which the rotate bond <angle> command will be applied. If no bond exists, it is created.
Rotation around a previously picked bond may be specified by the rotate bond <angle> command, or may also be controlled with the
mouse, using the bond rotate on/off or the equivalent rotate bond on/off commands.
Bulgarian
The RasMol Bulgarian command sets the menus and messages to the Bulgarian versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Cartoon
The RasMol cartoon command does a display of a molecule ribbons as Richardson (MolScript) style protein cartoons, implemented as
thick (deep) ribbons. The easiest way to obtain a cartoon representation of a protein is to use the Cartoons option on the Display
menu. The cartoon command represents the currently selected residues as a deep ribbon with width specified by the command's argu-
ment. Using the command without a parameter results in the ribbon's width being taken from the protein's secondary structure, as
described in the ribbons command. By default, the C-termini of beta-sheets are displayed as arrow heads. This may be enabled and
disabled using the set cartoons command. The depth of the cartoon may be adjusted using the set cartoons <number> command. The set
cartoons command without any parameters returns these two options to their default values.
Centre The RasMol centre command defines the point about which the rotate command and the scroll bars rotate the current molecule. Without
a parameter the centre command resets the centre of rotation to be the centre of gravity of the molecule. If an atom expression is
specified, RasMol rotates the molecule about the centre of gravity of the set of atoms specified by the expression. Hence, if a sin-
gle atom is specified by the expression, that atom will remain 'stationary' during rotations.
Type help expression for more information on RasMol atom expressions.
Alternatively the centring may be given as a comma separated triple of [CenX, CenY, CenZ] offsets in RasMol units (1/250 of an
Angstrom) from the centre of gravity. The triple must be enclosed in square brackets.
The optional forms centre ... translate and centre ... center may be used to specify use of a translated centre of rotation (not
necessarily in the centre of the canvas) or a centre of rotation which is placed at the centre of the canvas. Starting with RasMol
2.7.2, the default is to center the new axis on the canvas.
Chinese
The RasMol Chinese command sets the menus and messages to the Chinese versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Clipboard
The RasMol clipboard command places a copy of the currently displayed image on the local graphics 'clipboard'. Note: this command is
not yet supported on UNIX or VMS machines. It is intended to make transferring images between applications easier under Microsoft
Windows or on an Apple Macintosh.
When using RasMol on a UNIX or VMS system this functionality may be achieved by generating a raster image in a format that can be
read by the receiving program using the RasMol write command.
Colour Colour the atoms (or other objects) of the selected region. The colour may be given as either a colour name or a comma separated
triple of Red, Green and Blue (RGB) components enclosed in square brackets. Typing the command help colours will give a list of all
the predefined colour names recognised by RasMol.
Allowed objects are atoms, bonds, backbone, ribbons, labels, dots, hbonds, map, and ssbonds. If no object is specified, the default
keyword atom is assumed. Some colour schemes are defined for certain object types. The colour scheme none can be applied to all
objects except atoms and dots, stating that the selected objects have no colour of their own, but use the colour of their associated
atoms (i.e. the atoms they connect). Atom objects can also be coloured by alt, amino, chain, charge, cpk, group, model, shapely,
structure, temperature or user. Hydrogen bonds can also be coloured by type and dot surfaces can also be coloured by electrostatic
potential. For more information type help colour <colour>. Map objects may be coloured by specific color of by nearest atom.
ColourMode
ColourMode allows the user to switch between using the new colour method. At present, the new coloring technique is the same as the
old one, but to preserve compatibility for older scripts it may be wise to add a "colormode on" near the top of your script some-
where, if the script was designed for version 2.7.3 of RasMol or earlier. The new color method, when completed, aims to fix a few
bugs in the coloring routines.
Connect
The RasMol connect command is used to force RasMol to (re)calculate the connectivity of the current molecule. If the original input
file contained connectivity information, this is discarded. The command connect false uses a fast heuristic algorithm that is suit-
able for determining bonding in large bio-molecules such as proteins and nucleic acids. The command connect true uses a slower more
accurate algorithm based upon covalent radii that is more suitable to small molecules containing inorganic elements or strained
rings. If no parameters are given, RasMol determines which algorithm to use based on the number of atoms in the input file. Greater
than 255 atoms causes RasMol to use the faster implementation. This is the method used to determine bonding, if necessary, when a
molecule is first read in using the load command.
Defer The RasMol defer command adds the command given to the macro with given name, if no name is given, the command is added to the macro
with a blank name. The command zap is a special case. In that case the macro is erased. If no name is given the command must begin
with a selection, e.g. defer (selection).spacefill
The deferred commands accumulated under the given name can be executed using the execute command
Define The RasMol define command allows the user to associate an arbitrary set of atoms with a unique identifier. This allows the defini-
tion of user-defined sets. These sets are declared statically, i.e. once defined the contents of the set do not change, even if the
expression defining them depends on the current transformation and representation of the molecule.
Depth The RasMol depth command enables, disables or positions the back-clipping plane of the molecule. The program only draws those por-
tions of the molecule that are closer to the viewer than the clipping plane. Integer values range from zero at the very back of the
molecule to 100 which is completely in front of the molecule. Intermediate values determine the percentage of the molecule to be
drawn.
This command interacts with the slab <value> command, which clips to the front of a given z-clipping plane.
Dots The RasMol dots command is used to generate a van der Waals' dot surface around the currently selected atoms. Dot surfaces display
regularly spaced points on a sphere of van der Waals' radius about each selected atom. Dots that would are 'buried' within the van
der Waals' radius of any other atom (selected or not) are not displayed. The command dots on deletes any existing dot surface and
generates a dots surface around the currently selected atom set with a default dot density of 100. The command dots off deletes any
existing dot surface. The dot density may be specified by providing a numeric parameter between 1 and 1000. This value approximately
corresponds to the number of dots on the surface of a medium sized atom.
By default, the colour of each point on a dot surface is the colour of its closest atom at the time the surface is generated. The
colour of the whole dot surface may be changed using the colour dots command.
Echo The RasMol echo command is used to display a message in the RasMol command/terminal window. The string parameter may optionally be
delimited in double quote characters. If no parameter is specified, the echo command displays a blank line. This command is particu-
larly useful for displaying text from within a RasMol script file.
English
The RasMol English command sets the menus and messages to the English versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Execute
The RasMol execute command:
1. saves the old poise of the molecule (translation, rotation and zoom)
2. executes the specified macro suppressing both screen updates and recording
3. animates motion of the newly rendered molecule linearly from the old poise to the new poise
The macro must have been previously defined by calls to the defer command.
The animation of the motion depends on the prior settings of the record command.
French The RasMol French command sets the menus and messages to the French versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
HBonds The RasMol hbond command is used to represent the hydrogen bonding of the protein molecule's backbone. This information is useful in
assessing the protein's secondary structure. Hydrogen bonds are represented as either dotted lines or cylinders between the donor
and acceptor residues. The first time the hbond command is used, the program searches the structure of the molecule to find hydrogen
bonded residues and reports the number of bonds to the user. The command hbonds on displays the selected 'bonds' as dotted lines,
and the hbonds off turns off their display. The colour of hbond objects may be changed by the colour hbond command. Initially, each
hydrogen bond has the colours of its connected atoms.
By default the dotted lines are drawn between the accepting oxygen and the donating nitrogen. By using the set hbonds command the
alpha carbon positions of the appropriate residues may be used instead. This is especially useful when examining proteins in back-
bone representation.
Help The RasMol help command provides on-line help on the given topic.
Italian
The RasMol Italian command sets the menus and messages to the Italian versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Japanese
The RasMol Japanese command sets the menus and messages to the Japanese versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Label The RasMol label command allows an arbitrary formatted text string to be associated with each currently selected atom. This string
may contain embedded 'expansion specifiers' which display properties of the atom being labelled. An expansion specifier consists of
a '%' character followed by a single alphabetic character specifying the property to be displayed. An actual '%' character may be
displayed by using the expansion specifier '%%'.
Atom labelling for the currently selected atoms may be turned off with the command label off. By default, if no string is given as
a parameter, RasMol uses labels appropriate for the current molecule.
The colour of each label may be changed using the colour label command. By default, each label is drawn in the same colour as the
atom to which it is attached. The size and spacing of the displayed text may be changed using the set fontsize command. The width
of the strokes in the displayed text may be changed
using the set fontstroke
command.
Load Load a molecule coordinate file into RasMol. Valid molecule file formats are pdb (Protein Data Bank format), mdl (Molecular Design
Limited's MOL file format), alchemy (Tripos' Alchemy file format), mol2 (Tripos' Sybyl Mol2 file format), charmm (CHARMm file for-
mat), xyz (MSC's XMol XYZ file format), mopac (J. P. Stewart's MOPAC file format) or cif (IUCr CIF or mmCIF file format). If no file
format is specified, PDB, CIF, or mmCIF is assumed by default. Up to 20 molecules may be loaded at a time. If CHEM_COMP ligand mod-
els are included in an mmCIF file, they will be loaded as NMR models, first giving the all the NMR models for model coordinates if
specified and then giving all the NMR models for ideal model coordinates.
To delete a molecule prior to loading another use the RasMol zap command. To select a molecule for manipulation use the RasMol mol-
ecule <n> command.
The load command selects all the atoms in the molecule, centres it on the screen and renders it as a CPK coloured wireframe model.
If the molecule contains no bonds (i.e. contains only alpha carbons), it is drawn as an alpha carbon backbone. If the file specifies
fewer bonds than atoms, RasMol determines connectivity using the connect command.
The load inline command also allows the storing of atom coordinates in scripts to allow better integration with WWW browsers. A load
command executed inside a script file may specify the keyword inline instead of a conventional filename. This option specifies that
the coordinates of the molecule to load are stored in the same file as the currently executing commands.
Map The RasMol map commands manipulate electron density maps in coordination with the display of molecules. These commands are very
memory intensive and may not work on machines with limited memory. Each molecule may have as many maps as available memory permits.
Maps may be read from files or generated from Gaussian density distributions around atoms.
map colour, to colour a map according to a given colour scheme, map generate, to generate a map from selected atoms based on pseudo-
Gaussians, map level, to set the contouring level for selected maps, map load, to load a map from a file, map mask to designate a
mask for the selected maps, map resolution, to set the resolution for contouring selected maps, map restrict, to select one or more
maps and to disable all others, map save, to save map information to a file, map scale, control the scaling of pseudo-Gaussians when
generating maps, map select, to select one or more maps, map show, to display information about one or more maps or about the param-
eters to be used in generating or loading the next map, map spacing, to set the spacing betwen contour lines of selected maps, map
spread, to set the variance of the Gaussians for map generation as a fraction of the atomic radius, and map zap to delete previously
generated or loaded maps.
The effect of map generate and map load commands is modified by the map mask command which limits the portion of the display space
that can be considered for display of maps.
Map colour
The RasMol map colour command colours the selected maps according to the specified colour scheme. The colour scheme may be a colour
name or and RBG triple in brackets, or the keyword atom to cause the map points to be coloured by the color of the nearest atom.
Map generate
The RasMol map generate command generates a map from whatever atoms are currently selected, by summing electron densities approxi-
mated by Gaussian distributions. The height of each Gaussian is determined by the setting of the map scale command. In the default
of map scale true, each Gaussian has a height proportional element type of the atom. If the optional 'LRSurf' parameter is given or
if map scale false has been executed, each Gaussian is scaled so that the Gaussian contour level 1 is at the van der Waals radius.
In either case a standard deviation determined by the most recently specified spread or resolution is used. If a non-zero spread
has been given the radius of the atom is multiplied by the spread to find the standard deviation. The default is 2/3rds. If a res-
olution has been given, the spread is inferred as 2/3rds of the resolution.
For example, if the resolution is given as 1., and the atom in question is a Carbon with a van der Waals radius of 468 RasMol units
(1.87 Angstroms), the inferred spead is .6667, and the standard deviation of the Gaussian is taken as 1.25 Angstroms.
If the spread has been set to zero, the spread for each atom is determined from the van der Waals radius and the probe atom radius
to simulate the effect of a Lee-Richards surface.
If no specific map was given by the map selector, the new map is given the next available map number.
If a specific map was given by the map selector, the new map replaces that map. If more than one map was given by the map selector,
the new map replaces the lowest numbered of the selected maps. In any case the new map becomes the currently selected map.
The map is displayed as dots, mesh or a surface, depending on the last map rendering mode selected or the mode selected on the com-
mand itself.
Map level
The RasMol map level command sets the contour level to be used in creating subsequent representations of generated or loaded maps.
If the keyword MEAN in used the level is relative to the mean of the map data. Otherwise the level is absolute.
In general, a lower level results in a map containing more of the displayed volume, while a higher level results in a map containing
less of the displayed volume.
Map load
The RasMol map load command loads a map file into RasMol. The valid formats are CCP4 map format and imgCIF format.
If no specific map was given by the map selector, the new map is given the next available map number.
If a specific map was given by the map selector, the new map replaces that map. If more than one map was given by the map selector,
the new map replaces the lowest numbered of the selected maps. In any case the new map becomes the currently selected map.
The map is displayed as dots, mesh or a surface depending on the last map rendering mode selected.
Map mask
The RasMol map mask command specifies a mask to be used to limit the display space to be used for making representations of other
maps or removes an earlier mask specification.
The 'selected' option indicates that the mask is to be created from the currently selected atoms. The '<number>' option indicates
that the mask is to be copied from the map of the number specified. The 'none' option removes the previously specified mask, if
any.
The map selector specifies the map or maps to which the specified mask will the applied. For example, 'map next mask selected'
specifies that the currently selected atoms are to be used to generate a mask to be applied to any maps created by subsequent 'map
load' or 'map generate' commands.
Any map may be used as a mask. The portions of the mask map greater than than or equal to the average value of the mask map allow
the values of the map being masked to be used as given. The portions of the mask map lower than the average value of the mask map
cause the values of the map being masked to be treated as if they were equal to the lowest data value of the map being masked.
Map resolution
The RasMol map resolution command specifies the resolution in RasMol units or, if a number containing a decimal point is given, the
resolution in Angstroms to be used in generating and in representing maps.
The resolution is used at the map spacing for representations of maps, indicating the separation between contour levels (see the map
spacing command) and to infer the map spread to be used in generated maps from selected atoms (see the map spread command). The map
spread is set to two thirds of the specified resolution.
Map restrict
The RasMol map restrict command selects particular maps to make them active for subsequent map commands. This is similar to the map
select command, but does disables the display of the maps that were not selected.
Map save
The RasMol map save command saves an imgCIF map file.
If no specific map was given by the map selector, the currently selected maps and their masks are written to the file, one map and
mask pair per data block.
Map scale
The RasMol map scale command selects the scaling of pseudo-Gaussians in the map generate commands. In the default of map scale
true, each Gaussian has a height proportional element type of the atom. If map scale false has been executed, each Gaussian is
scaled so that the Gaussian contour level 1 is at the van der Waals radius. In either case a standard deviation determined by the
most recently specified spread or resolution is used.
Map select
The RasMol map select command selects particular maps to make them active for subsequent map commands. This is similar to the map
restrict command, but does not disable the display of the maps that were not selected.
If the optional atom parameter is given, the command selects the atoms with centres closest to the map points. The radius of the
search may be specified by the parameter search_radius. The default is to look for atoms within 4 Angstroms plus the probe radius.
If the optional within parameter is given, the new selection is taken from within the currently selected atoms. If the options add
parameter is given, the new selection is added to the currently selected atoms. The default is to search within all atoms.
Map show
The RasMol map show command causes information about the maps specified by the map selector to be written to the command window.
Map spacing
The RasMol map spacing command specifies the spacing to be used between contour lines in creating representations of maps. The
spacing is typically
given in Angstroms with a decimal point, but may also be specified in RasMol units (250ths of an Angstom) as an integer. For maps
loaded in grid coordinates that spacing is parallel to the cell edges. The default spacing is one half Angstrom.
Map spread
The RasMol map spread command specifies the reciprocal of the number of standard deviations per radius to be used in generating maps
as sums of Gaussians centered on atomic positions. The default spread is one two thirds (i.e. each radius covers 1.5 standard devi-
ations).
If the spread has been set to zero, the spread for each atom is determined from the van der Waals radius and the probe atom radius
to simulate the effect of a Lee-Richards surface.
Map zap
The RasMol map zap command removes the data and representations of the maps specified by the map selector. The map numbers of maps
that have not been removed are not changed.
Molecule
The RasMol molecule command selects one of up to 5 previously loaded molecules for active manipulation. While all the molcules are
displayed and may be rotated collectively (see the rotate all command), only one molecule at a time time is active for manipulation
by the commands which control the details of rendering.
Monitor
The RasMol monitor command allows the display of distance monitors. A distance monitor is a dashed (dotted) line between an arbi-
trary pair of atoms, optionally labelled by the distance between them. The RasMol command monitor <number> <number> adds such a
distance monitor between the two atoms specified by the atom serial numbers given as parameters
Distance monitors are turned off with the command monitors off. By default, monitors display the distance between its two end
points as a label at the centre of the monitor. These distance labels may be turned off with the command set monitors off, and re-
enabled with the command set monitors on. Like most other representations, the colour of a monitor is taken from the colour of its
end points unless specified by the colour monitors command.
Distance monitors may also be added to a molecule interactively with the mouse, using the set picking monitor command. Clicking on
an atom results in its being identified on the rasmol command line. In addition every atom picked increments a modulo counter such
that, in monitor mode, every second atom displays the distance between this atom and the previous one. The shift key may be used to
form distance monitors between a fixed atom and several consecutive positions. A distance monitor may also be removed (toggled) by
selecting the appropriate pair of atom end points a second time.
Notoggle
The RasMol NoToggle command enables or disables the use of the toggle ability that is used by some of the other RasMol commands.
When no boolean value is specified, NoToggle mode is ENABLED. When NoToggle mode is ENABLED, all toggle functionality is DISABLED.
To turn it off, one must explicitly set notoggle off.
Some commands which use the toggle feature are: ColourMode. More functions that utilize this capability may be added at a later
date.
Pause The RasMol pause command is used in script files to stop the script file for local manipulation by a mouse, until any key is pushed
to restart the script file. Wait is synonymous with pause. This command may be executed in RasMol script files to suspend the
sequential execution of commands and allow the user to examine the current image. When RasMol executes a pause command in a script
file, it suspends execution of the rest of the file, refreshes the image on the screen and allows the manipulation of the image
using the mouse and scroll bars, or resizing of the graphics window. Once a key is pressed, control returns to the script file at
the line following the pause command. While a script is suspended the molecule may be rotated, translated, scaled, slabbed and
picked as usual, but all menu commands are disabled.
Play The RasMol play command specifies the recording medium from which to play back a movie. The playback frame start time is given in
seconds to millisecond precision. Since we are working on computers, the medium is specified as a set of files, each marked with
the playback frame start time in milliseconds as part of the name. The place in the name at which to look for the playback frame
start time in milliseconds is marked by the characters "ssssss" with an appropriate number of digits. RasMol accepts either upper
or lower case s's or decimal digits to mark the place for the time. The play off and play eject commands effectively remove the
specified medium from use. If no medium is specified, play off suspends playing and play on resumes playing. Normally play starts
immediately and runs to the end of the medium. However, if play off and/or or some combination of play from and play until is
entered before play type medium, those settings will be used.
As of release 2.7.5, RasMol support play from scripts and data files.
Print The RasMol print command sends the currently displayed image to the local default printer using the operating system's native
printer driver. Note: this command is not yet supported under UNIX or VMS. It is intended to take advantage of Microsoft Windows and
Apple Macintosh printer drivers. For example, this allows images to be printed directly on a dot matrix printer.
When using RasMol on a UNIX or VMS system this functionality may be achieved by either generating a PostScript file using the RasMol
write ps or write vectps commands and printing that or generating a raster image file and using a utility to dump that to the local
printer.
Quit Exit from the RasMol program. The RasMol commands exit and quit are synonymous, except within nested scripts. In that case, exit
terminates only the current level, while quit terminates all nested levels of scripts.
Record The RasMol record command specifies the recording medium to hold the movie. Since we are working on computers, the medium is speci-
fied as a template for a set of files, each marked with the playback frame start time in milliseconds (rather than as seconds to
avoid embedding a decimal point) as part of the name. The place in the name to be replaced with the playback frame start time in
milliseconds is marked by the characters "ssssss" with an appropriate number of digits. RasMol accepts either upper or lower case
s's or decimal digits to mark the place for the time. The record off commands remove the specified medium from use. If no medium is
specified, record off suspends recording and record on resumes recording with the next available time on the same medium. The screen
is the default medium and is, by default, on. Writing to disk must be explicitly specified so that the disk does not get filled up
unintentionally. The type of a recording medium may be an image type such as gif, pict or png to record the actual screen images or
script to record the RasMol commands used to generate the frames.
Normally recording starts at playback frame start time 0 seconds. A non-zero starting time in seconds can be specified with the
record from command as in record from 25 or record from 37.25 to help in organizing scenes of movies to be assembled later in an
appropriate order. The record until command allows an upper limit to be set on recording time in seconds. The default is to have
no limit. Issuing the commands
record from 600
record until 1800
would result in a 20 minute movie segment intended to start 10 minutes into a longer movie. These commands allow control over
rewriting selected time segments.
Refresh
The RasMol refresh command redraws the current image. This is useful in scripts to ensure application of a complex list of parame-
ter changes.
Renumber
The RasMol renumber command sequentially numbers the residues in a macromolecular chain. The optional parameter specifies the value
of the first residue in the sequence. By default, this value is one. For proteins, each amino acid is numbered consecutively from
the N terminus to the C terminus. For nucleic acids, each base is numbered from the 5' terminus to the 3' terminus. All chains in
the current database are renumbered and gaps in the original sequence are ignored. The starting value for numbering may be negative.
Reset The RasMol reset command restores the original viewing transformation and centre of rotation. The scale is set to its default value,
zoom 100, the centre of rotation is set to the geometric centre of the currently loaded molecule, centre all, this centre is trans-
lated to the middle of the screen and the viewpoint set to the default orientation.
This command should not be mistaken for the RasMol zap command which deletes the currently stored molecule, returning the program to
its initial state.
Restrict
The RasMol restrict command both defines the currently selected region of the molecule and disables the representation of (most of)
those parts of the molecule no longer selected. All subsequent RasMol commands that modify a molecule's colour or representation
affect only the currently selected region. The parameter of a restrict command is a RasMol atom expression that is evaluated for
every atom of the current molecule. This command is very similar to the RasMol select command, except restrict disables the wire-
frame, spacefill and backbone representations in the non-selected region.
Type "help expression" for more information on RasMol atom expressions or see section Atom Expressions.
Ribbons
The RasMol ribbons command displays the currently loaded protein or nucleic acid as a smooth solid "ribbon" surface passing along
the backbone of the protein. The ribbon is drawn between each amino acid whose alpha carbon is currently selected. The colour of
the ribbon is changed by the RasMol colour ribbon command. If the current ribbon colour is none (the default), the colour is taken
from the alpha carbon at each position along its length.
The width of the ribbon at each position is determined by the optional parameter in the usual RasMol units. By default the width of
the ribbon is taken from the secondary structure of the protein or a constant value of 720 (2.88 Angstroms) for nucleic acids. The
default width of protein alpha helices and beta sheets is 380 (1.52 Angstroms) and 100 (0.4 Angstroms) for turns and random coil.
The secondary structure assignment is either from the PDB file or calculated using the DSSP algorithm as used by the structure com-
mand. This command is similar to the RasMol command strands which renders the biomolecular ribbon as parallel depth-cued curves.
Rotate Rotate the molecule about the specified axis. Permitted values for the axis parameter are "x", "y", "z" and "bond". The integer
parameter states the angle in degrees for the structure to be rotated. For the X and Y axes, positive values move the closest point
up and right, and negative values move it down and left, respectively. For the Z axis, a positive rotation acts clockwise and a neg-
ative angle anti-clockwise.
Alternatively, this command may be used to specify which rotations the mouse or dials will control. If rotate bond true is
selected, the horizontal scroll bar will control rotation around the axis selected by the bond src dst pick command. If rotate all
true is selected, and multiple molecules have been loaded, then all molecules will rotate together. In all other cases, the mouse-
and dials control the the rotation of the molecule selected by the molecule n command.
Russian
The RasMol Russian command sets the menus and messages to the Russian versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
Save Save the currently selected set of atoms in a Protein Data Bank (PDB), MDL, Alchemy(tm) or XYZ format file. The distinction between
this command and the RasMol write command has been dropped. The only difference is that without a format specifier the save command
generates a PDB file and the write command generates a GIF image.
Script The RasMol script command reads a set of RasMol commands sequentially from a text file and executes them. This allows sequences of
commonly used commands to be stored and performed by single command. A RasMol script file may contain a further script command up to
a maximum "depth" of 10, allowing complicated sequences of actions to be executed. RasMol ignores all characters after the first '#'
character on each line allowing the scripts to be annotated. Script files are often also annotated using the RasMol echo command.
The most common way to generate a RasMol script file is to use the write script or write rasmol commands to output the sequence of
commands that are needed to regenerate the current view, representation and colouring of the currently displayed molecule.
The RasMol command source is synonymous with the script command.
Select Define the currently selected region of the molecule. All subsequent RasMol commands that manipulate a molecule or modify its colour
or representation only affect the currently selected region. The parameter of a select command is a RasMol expression that is evalu-
ated for every atom of the current molecule. The currently selected (active) region of the molecule are those atoms that cause the
expression to evaluate true. To select the whole molecule use the RasMol command select all. The behaviour of the select command
without any parameters is determined by the RasMol hetero and hydrogen parameters.
Type "help expression" for more information on RasMol atom expressions or see section Atom Expressions.
Set The RasMol set command allows the user to alter various internal program parameters such as those controlling rendering options.
Each parameter has its own set or permissible parameter options. Typically, omitting the parameter option resets that parameter to
its default value. A list of valid parameter names is given below.
Show The RasMol show command display details of the status of the currently loaded molecule. The command show information lists the mole-
cule's name, classification, PDB code and the number of atoms, chains, groups it contains. If hydrogen bonding, disulphide bridges
or secondary structure have been determined, the number of hbonds, ssbonds, helices, ladders and turns are also displayed, respec-
tively. The command show centre shows any non-zero centering values selected by the centre [CenX, CenY, CenZ] command. The command
show phipsi shows the phi and psi angles of the currently selected residues and the omega angles of cis peptide bonds. The command
show RamPrint (or 'show RPP' or 'show RamachandranPrinterPlot') shows a simple Ramachandran printer plot in the style of Frances
Bernstein's fisipl program. The command show rotation (or 'show rot' or 'show 'rotate') shows the currently selected values of z,
y, x and bond rotations, if any. The command show selected (or 'show selected group' or 'show selected chain' or 'show selected
atom' ) shows the groups (default), chains or atoms of the current selection. The command show sequence lists the residues that
comprise each chain of the molecule. The command show symmetry shows the space group and unit cell of the molecule. The command
show translation shows any non-zero translation values selected by the translate <axis> <value> command. The command show zoom shows
any non-zero zoom value selected by the zoom <value> command.
Slab The RasMol slab command enables, disables or positions the z-clipping plane of the molecule. The program only draws those portions
of the molecule that are further from the viewer than the slabbing plane. Integer values range from zero at the very back of the
molecule to 100 which is completely in front of the molecule. Intermediate values determine the percentage of the molecule to be
drawn.
This command interacts with the depth <value> command, which clips to the rear of a given z-clipping plane.
Spacefill
The RasMol spacefill command is used to represent all of the currently selected atoms as solid spheres. This command is used to pro-
duce both union-of-spheres and ball-and-stick models of a molecule. The command, spacefill true, the default, represents each atom
as a sphere of van der Waals radius. The command spacefill off turns off the representation of the selected atom as spheres. A
sphere radius may be specified as an integer in RasMol units (1/250th Angstrom) or a value containing a decimal point. A value of
500 (2.0 Angstroms) or greater results in a "Parameter value too large" error.
The temperature option sets the radius of each sphere to the value stored in its temperature field. Zero or negative values have no
effect and values greater than 2.0 are truncated to 2.0. The user option allows the radius of each sphere to be specified by addi-
tional lines in the molecule's PDB file using Raster 3D's COLOUR record extension.
The RasMol command cpk is synonymous with the spacefill command.
The RasMol command cpknew is synonymous with the spacefill command, except that a slightly different set of colours is used.
Spanish
The RasMol Spanish command sets the menus and messages to the Spanish versions.
This command may not work correctly unless appropriate fonts have been installed. The commands Bulgarian, Chinese, English, French,
Italian, Russian and Spanish may be used to select Bulgarian, Chinese, English, French, Italian, Japanese, Russian and Spanish menus
and messages if the appropriate fonts have been installed.
SSBonds
The RasMol ssbonds command is used to represent the disulphide bridges of the protein molecule as either dotted lines or cylinders
between the connected cysteines. The first time that the ssbonds command is used, the program searches the structure of the protein
to find half-cysteine pairs (cysteines whose sulphurs are within 3 Angstroms of each other) and reports the number of bridges to the
user. The command ssbonds on displays the selected "bonds" as dotted lines, and the command ssbonds off disables the display of
ssbonds in the currently selected area. Selection of disulphide bridges is identical to normal bonds, and may be adjusted using the
RasMol set bondmode command. The colour of disulphide bonds may be changed using the colour ssbonds command. By default, each disul-
phide bond has the colours of its connected atoms.
By default disulphide bonds are drawn between the sulphur atoms within the cysteine groups. By using the set ssbonds command the
position of the cysteine's alpha carbons may be used instead.
Star The RasMol star command is used to represent all of the currently selected atoms as stars (six strokes, one each in the x, -x, y,
-y, z and -z directions). The commands select not bonded followed by star 75 are useful to mark unbonded atoms in a wireframe dis-
play with less overhead than provided by spacefill 75. This can be done automatically for all subsequent wireframe displays with
the command set bondmode not bonded.
The command star true, the default, represents each atom as a star with strokes length equal to van der Waals radius. The command
star off turns off the representation of the selected atom as stars. A star stroke length may be specified as an integer in RasMol
units (1/250th Angstrom) or a value containing a decimal point. A value of 500 (2.0 Angstroms) or greater results in a "Parameter
value too large" error.
The temperature option sets the stroke length of each star to the value stored in its temperature field. Zero or negative values
have no effect and values greater than 2.0 are truncated to 2.0. The user option allows the stroke length of each star to be speci-
fied by additional lines in the molecule's PDB file using Raster 3D's COLOUR record extension.
The RasMol spacefill command can be used for more artistic rendering of atoms as spheres.
Stereo The RasMol stereo command provides side-by-side stereo display of images. Stereo viewing of a molecule may be turned on (and off)
either by selecting Stereo from the Options menu, or by typing the commands stereo on or stereo off.
Starting with RasMol version 2.7.2.1, the Stereo menu selection and the command stereo without arguments cycle from the initial
state of stereo off to stereo on in cross-eyed mode to stereo on in wall-eyed mode and then back to stereo off.
The separation angle between the two views may be adjusted with the set stereo [-] <number> command, where positive values result in
crossed eye viewing and negative values in relaxed (wall-eyed) viewing. The inclusion of [-] <number> in the stereo command, as for
example in stereo 3 or stereo -5, also controls angle and direction.
The stereo command is only partially implemented. When stereo is turned on, the image is not properly recentred. (This can be done
with a translate x -<number>
command.) It is not supported in vector PostScript output files, is not saved by the write script command, and in general is not
yet properly interfaced with several other features of the program.
Strands
The RasMol strands command displays the currently loaded protein or nucleic acid as a smooth "ribbon" of depth-cued curves passing
along the backbone of the protein. The ribbon is composed of a number of strands that run parallel to one another along the peptide
plane of each residue. The ribbon is drawn between each amino acid whose alpha carbon is currently selected. The colour of the rib-
bon is changed by the RasMol colour ribbon command. If the current ribbon colour is none (the default), the colour is taken from the
alpha carbon at each position along its length. The central and outermost strands may be coloured independently using the colour
ribbon1 and colour ribbon2 commands, respectively. The number of strands in the ribbon may be altered using the RasMol set strands
command.
The width of the ribbon at each position is determined by the optional parameter in the usual RasMol units. By default the width of
the ribbon is taken from the secondary structure of the protein or a constant value of 720 for nucleic acids (which produces a rib-
bon 2.88 Angstroms wide). The default width of protein alpha helices and beta sheets is 380 (1.52 Angstroms) and 100 (0.4
Angstroms) for turns and random coil. The secondary structure assignment is either from the PDB file or calculated using the DSSP
algorithm as used by the structure command. This command is similar to the RasMol command ribbons which renders the biomolecular
ribbon as a smooth shaded surface.
Structure
The RasMol structure command calculates secondary structure assignments for the currently loaded protein. If the original PDB file
contained structural assignment records (HELIX, SHEET and TURN) these are discarded. Initially, the hydrogen bonds of the current
molecule are found, if this hasn't been done already. The secondary structure is then determined using Kabsch and Sander's DSSP
algorithm. Once finished the program reports the number of helices, strands and turns found.
Surface
The RasMol surface command renders a Lee-Richards molecular surface resulting from rolling a probe atom on the selected atoms. The
value given specifies the radius of the probe. If given in the first form, the evolute of the surface of the probe is shown (the
solvent excluded surface). If given in the second form, the envelope of the positions of the center of the probe is shown (the sol-
vent accessible surface).
Trace The RasMol trace command displays a smooth spline between consecutive alpha carbon positions. This spline does not pass exactly
through the alpha carbon position of each residue, but follows the same path as ribbons, strands and cartoons. Note that residues
may be displayed as ribbons, strands, cartoons or as a trace. Enabling one of these representations disables the others. However, a
residue may be displayed simultaneously as backbone and as one of the above representations. This may change in future versions of
RasMol. Prior to version 2.6, trace was synonymous with backbone.
Trace temperature displays the backbone as a wider cylinder at high temperature factors and thinner at lower. This representation
is useful to X-ray crystallographers and NMR spectroscopists.
Translate
The RasMol translate command moves the position of the centre of the molecule on the screen. The axis parameter specifies along
which axis the molecule is to be moved and the integer parameter specifies the absolute position of the molecule centre from the
middle of the screen. Permitted values for the axis parameter are "x", "y" and "z". Displacement values must be between -100 and
100 which correspond to moving the current molecule just off the screen. A positive "x" displacement moves the molecule to the
right, and a positive "y" displacement moves the molecule down the screen. The pair of commands translate x 0 and translate y 0 cen-
tres the molecule on the screen.
UnBond The RasMol command unbond <number> <number> removes the designated bond from the drawing.
The command unbond without arguments removes a bond previously picked by the bond <number> <number> pick command.
Wireframe
The RasMol wireframe command represents each bond within the selected region of the molecule as a cylinder, a line or a depth-cued
vector. The display of bonds as depth-cued vectors (drawn darker the further away from the viewer) is turned on by the command wire-
frame or wireframe on. The selected bonds are displayed as cylinders by specifying a radius either as an integer in RasMol units or
containing a decimal point as a value in Angstroms. A parameter value of 500 (2.0 Angstroms) or above results in an "Parameter
value too large" error. Bonds may be coloured using the colour bonds command.
If the selected bonds involved atoms of alternate conformers then the bonds are narrowed in the middle to a radius of .8 of the
specified radius (or to the radius specified as the optional second parameter).
Non-bonded atoms, which could become invisible in an ordinary wireframe display can be marked by a preceding set bondmode not bonded
command. If nearly co-linear bonds to atoms cause them to be difficult to see in a wireframe display, the set bondmode all command
will add markers for all atoms in subsequent wireframe command executions.
Write Write the current image to a file in a standard format. Currently supported image file formats include bmp (Microsoft bitmap) and
gif (Compuserve GIF), iris (IRIS RGB), ppm (Portable Pixmap), ras (Sun rasterfile), ps and epsf (Encapsulated PostScript), monops
(Monochrome Encapsulated PostScript), pict (Apple PICT), vectps (Vector Postscript). The write command may also be used to generate
command scripts for other graphics programs. The format script writes out a file containing the RasMol script commands to reproduce
the current image. The format molscript writes out the commands required to render the current view of the molecule as ribbons in
Per Kraulis' Molscript program and the format kinemage the commands for David Richardson's program Mage. The following formats are
useful for further processing: povray (POVRay 2), povray3 (POVRay 3 -- under development), vrml (VRML file). Finally, several for-
mats are provided to provide phi-psi data for listing or for phipsi (phi-psi data as an annotated list with cis omegas), ramachan
and RDF and RamachandranDataFile (phi-psi data as columns of numbers for gnuplot), RPP and RamachandranPrinterPlot (phi-psi data as
a printer plot).
The distinction between this command and the RasMol save command has been dropped. The only difference is that without a format
specifier the save command generates a PDB file and the write command generates a GIF image.
Zap Deletes the contents of the current database and resets parameter variables to their initial default state.
Zoom Change the magnification of the currently displayed image. Boolean parameters either magnify or reset the scale of current molecule.
An integer parameter specifies the desired magnification as a percentage of the default scale. The minimum parameter value is 10;
the maximum parameter value is dependent upon the size of the molecule being displayed. For medium sized proteins this is about 500.
SET PARAMETERS
RasMol has a number of internal parameters that may be modified using the set command. These parameters control a number of program options
such as rendering options and mouse button mappings.
picking play.fps radius record.aps
Set Ambient
The RasMol ambient parameter is used to control the amount of ambient (or surrounding) light in the scene. The ambient value must be
between 0 and 100. It controls the percentage intensity of the darkest shade of an object. For a solid object, this is the intensity
of surfaces facing away from the light source or in shadow. For depth-cued objects this is the intensity of objects furthest from
the viewer.
This parameter is commonly used to correct for monitors with different "gamma values" (brightness), to change how light or dark a
hardcopy image appears when printed or to alter the feeling of depth for wireframe or ribbon representations.
Set Axes
The RasMol axes parameter controls the display of orthogonal coordinate axes on the current display. The coordinate axes are those
used in the molecule data file, and the origin is the centre of the molecule's bounding box. The set axes command is similar to the
commands set boundbox and set unitcell that display the bounding box and the crystallographic unit cell, respectively.
Set Backfade
The RasMol backfade parameter is used to control backfade to the specified background colour, rather than black. This is controlled
by the commands set backfade on and set backfade off. For example, this may be used to generate depth-cued images that fade to
white, rather than black.
Set Background
The RasMol background parameter is used to set the colour of the "canvas" background. The colour may be given as either a colour
name or a comma separated triple of Red, Green, Blue (RGB) components enclosed in square brackets. Typing the command help colours
will give a list of the predefined colour names recognised by RasMol. When running under X Windows, RasMol also recognises colours
in the X server's colour name database.
The command set background is synonymous with the RasMol command background.
Set BondMode
The RasMol set bondmode command controls the mechanism used to select individual bonds and modifies the display of bonded and non-
bonded atoms by subsequent wireframe commands.
When using the select and restrict commands, a given bond will be selected if i) the bondmode is or and either of the connected
atoms is selected, or ii) the bondmode is and and both atoms connected by the bond are selected. Hence an individual bond may be
uniquely identified by using the command set bondmode and and then uniquely selecting the atoms at both ends.
The bondmode [all | none | not bonded] commands add star 75 or spacefill 75 markers for the designated atoms to wireframe displays.
Stars are used when the specified wireframe radius is zero.
Set Bonds
The RasMol bonds parameter is used to control display of double and triple bonds as multiple lines or cylinders. Currently bond
orders are only read from MDL Mol files, Sybyl Mol2 format files, Tripos Alchemy format files, CIF and mmCIF, and suitable PDB
files. Double (and triple) bonds are specified in some PDB files by specifying a given bond twice (and three times) in CONECT
records. The command set bonds on enables the display of bond orders, and the command set bonds off disables them.
Set BoundBox
The RasMol boundbox parameter controls the display of the current molecule's bounding box on the display. The bounding box is
orthogonal to the data file's original coordinate axes. The set boundbox command is similar to the commands set axes and set unit-
cell that display orthogonal coordinate axes and the bounding box, respectively.
Set Cartoon
The RasMol cartoon parameter is used to control display of the cartoon version of the ribbons display. By default, the C-termini of
beta-sheets are displayed as arrow heads. This may be enabled and disabled using the set cartoons <boolean> command. The depth of
the cartoon may be adjusted using the cartoons <number> command. The set cartoons command without any parameters returns these two
options to
their default values.
Set CisAngle
The RasMol cisangle parameter controls the cutoff angle for identifying cis peptide
bonds. If no value is given, the cutoff is set to 90 degrees.
Set Display
This command controls the display mode within RasMol. By default, set display normal, RasMol displays the molecule in the represen-
tation specified by the user. The command set display selected changes the display mode such that the molecule is temporarily drawn
so as to indicate currently selected portion of the molecule. The user specified colour scheme and representation remains unchanged.
In this representation all selected atoms are shown in yellow and all non selected atoms are shown in blue. The colour of the back-
ground is also changed to a dark grey to indicate the change of display mode. This command is typically only used by external
Graphical User Interfaces (GUIs).
Set FontSize
The RasMol set fontsize command is used to control the size of the characters that form atom labels. This value corresponds to the
height of the displayed character in pixels. The maximum value of fontsize is 48 pixels, and the default value is 8 pixels high.
Fixed or proportional spacing may be selected by appending the "FS" or "PS" modifiers, respectively. The default is "FS". To dis-
play atom labels on the screen use the RasMol label command and to change the colour of displayed labels, use the colour labels com-
mand.
Set FontStroke
The RasMol set fontstroke command is used to control the size of the stroke width of the characters that form atom labels. This
value is the radius in pixels of cylinders used to form the strokes. The special value of "0" is the default used for the normal
single pixel stroke width, which allows for rapid drawing and rotation of the image. Non-zero values are provided to allow for more
artistic atom labels for publication at the expense of extra time in rendering the image.
When wider strokes are used, a larger font size is recommend, e.g. by using the RasMol set fontsize 24 PS command, followed by set
fontstroke 2
To display atom labels on the screen use the RasMol label command, and to change the colour of displayed labels use the colour
labels command.
Set HBonds
The RasMol hbonds parameter determines whether hydrogen bonds are drawn between the donor and acceptor atoms of the hydrogen bond,
set hbonds sidechain or between the alpha carbon atoms of the protein backbone and between the phosphorous atoms of the nucleic acid
backbone, set hbonds backbone. The actual display of hydrogen bonds is controlled by the hbonds command. Drawing hydrogen bonds
between protein alpha carbons or nucleic acid phosphorous atoms is useful when the rest of the molecule is shown in only a schematic
representation such as backbone, ribbons or strands. This parameter is similar to the RasMol ssbonds parameter.
Set Hetero
The RasMol hetero parameter is used to modify the 'default' behaviour of the RasMol select command, i.e. the behaviour of select
without any parameters. When this value is false, the default select region does not include any heterogeneous atoms (refer to the
predefined set hetero ). When this value is true, the default select region may contain hetero atoms. This parameter is similar to
the RasMol hydrogen parameter which determines whether hydrogen atoms should be included in the default set. If both hetero and
hydrogen are true, select without any parameters is equivalent to select all.
Set HourGlass
The RasMol hourglass parameter allows the user to enable and disable the use of the 'hour glass' cursor used by RasMol to indicate
that the program is currently busy drawing the next frame. The command set hourglass on enables the indicator, whilst set hourglass
off prevents RasMol from changing the cursor. This is useful when spinning the molecule, running a sequence of commands from a
script file or using interprocess communication to execute complex sequences of commands. In these cases a 'flashing' cursor may be
distracting.
Set Hydrogen
The RasMol hydrogen parameter is used to modify the "default" behaviour of the RasMol select command, i.e. the behaviour of select
without any parameters. When this value is false, the default select region does not include any hydrogen, deuterium or tritium
atoms (refer to the predefined set hydrogen ). When this value is true, the default select region may contain hydrogen atoms. This
parameter is similar to the RasMol hetero parameter which determines whether heterogeneous atoms should be included in the default
set. If both hydrogen and hetero are true, select without any parameters is equivalent to select all.
Set Kinemage
The RasMol set kinemage command controls the amount of detail stored in a Kinemage output file generated by the RasMol write
kinemage command. The output kinemage files are intended to be displayed by David Richardson's Mage program. set kinemage false,
the default, only stores the currently displayed representation in the generated output file. The command set kinemage true, gener-
ates a more complex Kinemage that contains both the wireframe and backbone representations as well as the coordinate axes, bounding
box and crystal unit cell.
Set Menus
The RasMol set menus command enables the canvas window's menu buttons or menu bar. This command is typically only used by graphical
user interfaces or to create as large an image as possible when using Microsoft Windows.
Set Monitor
The RasMol set monitor command enables monitors. The distance monitor labels may be turned off with the command set monitor off,
and re-enabled with the command set monitor on.
Set Mouse
The RasMol set mouse command sets the rotation, translation, scaling and zooming mouse bindings. The default value is rasmol which
is suitable for two button mice (for three button mice the second and third buttons are synonymous); X-Y rotation is controlled by
the first button, and X-Y translation by the second. Additional functions are controlled by holding a modifier key on the keyboard.
[Shift] and the first button performs scaling, [shift] and the second button performs Z-rotation, and [control] and the first mouse
button controls the clipping plane. The insight and quanta options provide the same mouse bindings as other packages for experienced
users.
Set Picking
The RasMol set picking series of commands affects how a user may interact with a molecule displayed on the screen in RasMol.
Enabling/Disabling Atom Identification Picking: Clicking on an atom with the mouse results in identification and the display of its
residue name, residue number, atom name, atom serial number and chain in the command window. This behavior may be disabled with the
command set picking none and restored with the command set picking ident. The command set picking coord adds the atomic coordinates
of the atom to the display.
Disabling picking, by using set picking off is useful when executing the pause command in RasMol scripts as it prevents the display
of spurious message on the command line while the script is suspended.
Measuring Distances, Angles and Torsions: Interactive measurement of distances, angles and torsions is achieved using the commands:
set picking distance, set picking monitor, set picking angle and set picking torsion, respectively. In these modes, clicking on an
atom results in it being identified on the rasmol command line. In addition every atom picked increments a modulo counter such that
in distance mode, every second atom displays the distance (or distance monitor) between this atom and the previous one. In angle
mode, every third atom displays the angle between the previous three atoms and in torsion mode every fourth atom displays the tor-
sion between the last four atoms. By holding down the shift key while picking an atom, this modulo counter is not incremented and
allows, for example, the distances of consecutive atoms from a fixed atom to be displayed. See the monitor command for how to con-
trol the display of distance monitor lines and labels.
Labelling Atoms with the Mouse: The mouse may also be used to toggle the display of an atom label on a given atom. The RasMol com-
mand set picking label removes a label from a picked atom if it already has one or displays a concise label at that atom position
otherwise.
Centring Rotation with the Mouse: A molecule may be centred on a specified atom position using the RasMol commands set picking cen-
tre or set picking center. In this mode, picking an atom causes all futher rotations to be about that point.
Picking a Bond as a Rotation Axis: Any bond may be picked as an axis of rotation for the portion of the molecule beyond the second
atom selected. This feature should be used with caution, since, naturally, it changes the conformation of the molecule. After exe-
cuting set picking bond or using the equivalent "Pick Bond" in the "Settings" menu, a bond to be rotated is picked with the same
sort of mouse clicks as are used for picking atoms for a distance measurement. Normally this should be done where a bond exists,
but if no bond exists, it will be added. The bond cannot be used for rotation if it is part of a ring of any size. All bonds
selected for rotation are remembered so that they can be properly reported when writing a script, but only the most recently
selected bond may be actively rotated.
Enabling Atom/Group/Chain Selection Picking: Atoms, groups and chains may be selected (as if with the select command), with the set
picking atom, set picking group, set picking chain commands. For each of these commands, the shift key may be used to have a new
selection added to the old, and the control key may be used to have a new selection deleted from the old. When the set picking atom
command is given, the mouse can be used to pick or to drag a box around the atoms for which selection is desired. When the set
picking group command is given, picking any an atom will cause selection of all atoms which agree in residue number with the picked
atom, even if in different chains. When the set picking chain command is given, picking any atom will cause selection of all atoms
which agree in chain identifier with the picked atom.
Set Play
The RasMol set play.fps command gives the number of frames per second for playback by the play command (default 24 frames per sec-
ond).
In the current release of RasMol, the play timing is not controlled by this parameter.
Set Radius
The RasMol set radius command is used to alter the behaviour of the RasMol dots command depending upon the value of the solvent
parameter. When solvent is true, the radius parameter controls whether a true van der Waals' surface is generated by the dots com-
mand. If the value of radius is anything other than zero, that value is used as the radius of each atom instead of its true vdW
value. When the value of solvent is true, this parameter determines the 'probe sphere' (solvent) radius. The parameter may be given
as an integer in rasmol units or containing a decimal point in Angstroms. The default value of this parameter is determined by the
value of solvent and changing solvent resets radius to its new default value.
Set Record
The RasMol set record.aps gives the maximum on-screen velocity in Angstroms per second in animating translations, rotations and
zooms (default 10 A/second).
The RasMol set record.aps command gives number of frames per second for recording by the record command (default 24 frames per sec-
ond).
The RasMol set record.dwell command sets the time in seconds to dwell on a change in appearance (default .5 sec).
Set ShadePower
The shadepower parameter (adopted from RasTop) determines the shade repartition (the contrast) used in rendering solid objects. This
value between 0 and 100 adjusts shading on an object surface oriented along the direction to the light source. Changing the shade-
power parameter does not change the maximum or the minimum values of this shading, as does changing the ambient parameter. A value
of 100 concentrates the light on the top of spheres, giving a highly specular, glassy rendering (see the specpower parameter). A
value of 0 distributes the light on the entire object.
This implementation of shadepower differs from the one in RasTop only in the choice of range (0 to 100 versus -20 to 20 in RasTop).
Set Shadow
The RasMol set shadow command enables and disables ray-tracing of the currently rendered image. Currently only the spacefilling
representation is shadowed or can cast shadows. Enabling shadowing will automatically disable the Z-clipping (slabbing) plane using
the command slab off. Ray-tracing typically takes about several seconds for a moderately sized protein. It is recommended that
shadowing be normally disabled whilst the molecule is being transformed or manipulated, and only enabled once an appropriate view-
point is selected, to provide a greater impression of depth.
Set SlabMode
The RasMol slabmode parameter controls the rendering method of objects cut by the slabbing (z-clipping) plane. Valid slabmode param-
eters are "reject", "half", "hollow", "solid" and "section".
Set Solvent
The RasMol set solvent command is used to control the behaviour of the RasMol dots command. Depending upon the value of the solvent
parameter, the dots command either generates a van der Waals' or a solvent accessible surface around the currently selected set of
atoms. Changing this parameter automatically resets the value of the RasMol radius parameter. The command set solvent false, the
default value, indicates that a van der Waals' surface should be generated and resets the value of radius to zero. The command set
solvent true indicates that a 'Connolly' or 'Richards' solvent accessible surface should be drawn and sets the radius parameter, the
solvent radius, to 1.2 Angstroms (or 300 RasMol units).
Set Specular
The RasMol set specular command enables and disables the display of specular highlights on solid objects drawn by RasMol. Specular
highlights appear as white reflections of the light source on the surface of the object. The current RasMol implementation uses an
approximation function to generate this highlight.
The specular highlights on the surfaces of solid objects may be altered by using the specular reflection coefficient, which is
altered using the RasMol set specpower command.
Set SpecPower
The specpower parameter determines the shininess of solid objects rendered by RasMol. This value between 0 and 100 adjusts the
reflection coefficient used in specular highlight calculations. The specular highlights are enabled and disabled by the RasMol set
specular command. Values around 20 or 30 produce plastic looking surfaces. High values represent more shiny surfaces such as met-
als, while lower values produce more diffuse/dull surfaces.
Set SSBonds
The RasMol ssbonds parameter determines whether disulphide bridges are drawn between the sulphur atoms in the sidechain (the
default) or between the alpha carbon atoms in the backbone of the cysteines residues. The actual display of disulphide bridges is
controlled by the ssbonds command. Drawing disulphide bridges between alpha carbons is useful when the rest of the protein is shown
in only a schematic representation such as backbone, ribbons or strands. This parameter is similar to the RasMol hbonds parameter.
Set Stereo
The RasMol set stereo parameter controls the separation between the left and right images. Turning stereo on and off doesn't reposi-
tion the centre of the molecule.
Stereo viewing of a molecule may be turned on (and off) either by selecting Stereo from the Options menu, or by typing the commands
stereo on or stereo off.
The separation angle between the two views may be adjusted with the set stereo [-] <number> command, where positive values result in
crossed eye viewing and negative values in relaxed (wall-eyed) viewing. Currently, stereo viewing is not supported in vector Post-
Script output files.
Set Strands
The RasMol strands parameter controls the number of parallel strands that are displayed in the ribbon representations of proteins.
The permissible values for this parameter are 1, 2, 3, 4, 5 and 9. The default value is 5. The number of strands is constant for all
ribbons being displayed. However, the ribbon width (the separation between strands) may be controlled on a residue by residue basis
using the RasMol ribbons command.
Set Transparent
The RasMol transparent parameter controls the writing of transparent GIFs by the write gif <filename> command. This may be con-
trolled by the set transparent on and set transparent off commands.
Set UnitCell
The RasMol unitcell parameter controls the display of the crystallographic unit cell on the current display. The crystal cell is
only enabled if the appropriate crystal symmetry information is contained in the PDB, CIF or mmCIF data file. The RasMol command
show symmetry display details of the crystal's space group and unit cell axes. The set unitcell command is similar to the commands
set axes and set boundbox that display orthogonal coordinate axes and the bounding box, respectively.
Set VectPS
The RasMol vectps parameter is use to control the way in which the RasMol write command generates vector PostScript output files.
The command set vectps on enables the use of black outlines around spheres and cylinder bonds producing "cartoon-like" high resolu-
tion output. However, the current implementation of RasMol incorrectly cartoons spheres that are intersected by more than one other
sphere. Hence "ball and stick" models are rendered correctly but not large spacefilling spheres models. Cartoon outlines can be dis-
abled, the default, by the command set vectps off.
Set Write
The RasMol write parameter controls the use of the save and write commands within scripts, but it may only be executed from the com-
mand line. By default, this value is false, prohibiting the generation of files in any scripts executed at start-up (such as those
launched from a WWW browser). However, animators may start up RasMol interactively: type set write on and then execute a script to
generate each frame using the source command.
ATOM EXPRESSIONS
RasMol atom expressions uniquely identify an arbitrary group of atoms within a molecule. Atom expressions are composed of either primitive
expressions, predefined sets, comparison operators, within expressions, or logical (boolean) combinations of the above expression types.
The logical operators allow complex queries to be constructed out of simpler ones using the standard boolean connectives and, or and not.
These may be abbreviated by the symbols "&", "|" and "!", respectively. Parentheses (brackets) may be used to alter the precedence of the
operators. For convenience, a comma may also be used for boolean disjunction.
The atom expression is evaluated for each atom, hence protein and backbone selects protein backbone atoms, not the protein and [nucleic]
acid backbone atoms!
Primitive Expressions
RasMol primitive expressions are the fundamental building blocks of atom expressions. There are two types of primitive expression.
The first type is used to identify a given residue number or range of residue numbers. A single residue is identified by its number
(position in the sequence), and a range is specified by lower and upper bounds separated by a hyphen character. For example select
5,6,7,8 is also select 5-8. Note that this selects the given residue numbers in all macromolecule chains.
The second type of primitive expression specifies a sequence of fields that must match for a given atom. The first part specifies a
residue (or group of residues) and an optional second part specifies the atoms within those residues. The first part consists of a
residue name, optionally followed by a residue number and/or chain identifier.
The second part consists of a period character followed by an atom name. An atom name may be up to four alphabetic or numeric char-
acters. An optional semicolon followed by an alternate conformation identifier may be appended. An optional slash followed by a
model number may also be appended.
An asterisk may be used as a wild card for a whole field and a question mark as a single character wildcard.
Comparison Operators
Parts of a molecule may also be distinguished using equality, inequality and ordering operators on their properties. The format of
such comparison expression is a property name, followed by a comparison operator and then an integer value.
The atom properties that may be used in RasMol are atomno for the atom serial number, elemno for the atom's atomic number (element),
resno for the residue number, radius for the spacefill radius in RasMol units (or zero if not represented as a sphere) and tempera-
ture for the PDB isotropic temperature value.
The equality operator is denoted either "=" or "==". The inequality operator as either "<>", "!=" or "/=". The ordering operators
are "<" for less than, "<=" for less than or equal to, ">" for greater than, and ">" for greater than or equal to.
Within Expressions
A RasMol within expression allows atoms to be selected on their proximity to another set of atoms. A within expression takes two
parameters separated by a comma and surrounded by parentheses. The first argument is an integer value called the "cut-off" distance
of the within expression and the second argument is any valid atom expression. The cut-off distance is expressed in either integer
RasMol units or Angstroms containing a decimal point. An atom is selected if it is within the cut-off distance of any of the atoms
defined by the second argument. This allows complex expressions to be constructed containing nested within expressions.
For example, the command select within(3.2,backbone) selects any atom within a 3.2 Angstrom radius of any atom in a protein or
nucleic acid backbone. Within expressions are particularly useful for selecting the atoms around an active site.
Predefined Sets
RasMol atom expressions may contain predefined sets. These sets are single keywords that represent portions of a molecule of inter-
est. Predefined sets are often abbreviations of primitive atom expressions. In some cases the use of predefined sets allows selec-
tion of areas of a molecule that could not otherwise be distinguished. A list of the currently predefined sets is given below. In
addition to the sets listed here, RasMol also treats element names (and their plurals) as predefined sets containing all atoms of
that element type, i.e. the command select oxygen is equivalent to the command select elemno=8.
Predefined Sets
AT Set This set contains the atoms in the complementary nucleotides adenosine and thymidine (A and T, respectively). All nucleotides are
classified as either the set at or the set cg This set is equivalent to the RasMol atom expressions a,t, and nucleic and not cg.
Acidic Set
The set of acidic amino acids. These are the residue types Asp and Glu. All amino acids are classified as either acidic, basic or
neutral. This set is equivalent to the RasMol atom expressions asp, glu and amino and not (basic or neutral).
Acyclic Set
The set of atoms in amino acids not containing a cycle or ring. All amino acids are classified as either cyclic or acyclic. This
set is equivalent to the RasMol atom expression amino and not cyclic.
Aliphatic Set
This set contains the aliphatic amino acids. These are the amino acids Ala, Gly, Ile, Leu and Val. This set is equivalent to the
RasMol atom expression ala, gly, ile, leu, val.
Alpha Set
The set of alpha carbons in the protein molecule. This set is approximately equivalent to the RasMol atom expression *.CA. This
command should not be confused with the predefined set helix which contains the atoms in the amino acids of the protein's alpha
helices.
Amino Set
This set contains all the atoms contained in amino acid residues. This is useful for distinguishing the protein from the nucleic
acid and heterogeneous atoms in the current molecule database.
Aromatic Set
The set of atoms in amino acids containing aromatic rings. These are the amino acids His, Phe, Trp and Tyr. Because they contain
aromatic rings all members of this set are member of the predefined set cyclic. This set is equivalent to the RasMol atom expres-
sions his, phe, trp, tyr and cyclic and not pro.
Backbone Set
This set contains the four atoms of each amino acid that form the polypeptide N-C-C-O backbone of proteins, and the atoms of the
sugar phosphate backbone of nucleic acids. Use the RasMol predefined sets protein and nucleic to distinguish between the two forms
of backbone. Atoms in nucleic acids and proteins are either backbone or sidechain. This set is equivalent to the RasMol expression
(protein or nucleic) and not sidechain.
The predefined set mainchain is synonymous with the set backbone.
Basic Set
The set of basic amino acids. These are the residue types Arg, His and Lys. All amino acids are classified as either acidic, basic
or neutral. This set is equivalent to the RasMol atom expressions arg, his, lys and amino and not (acidic or neutral).
Bonded Set
This set contain all the atoms in the current molecule database that are bonded to at least one other atom.
Buried Set
This set contains the atoms in those amino acids that tend (prefer) to be buried inside protein, away from contact with solvent mol-
ecules. This set refers to the amino acids preference and not the actual solvent accessibility for the current protein. All amino
acids are classified as either surface or buried. This set is equivalent to the RasMol atom expression amino and not surface.
CG Set This set contains the atoms in the complementary nucleotides cytidine and guanosine (C and G, respectively). All nucleotides are
classified as either the set at or the set cg This set is equivalent to the RasMol atom expressions c,g and nucleic and not at.
Charged Set
This set contains the charged amino acids. These are the amino acids that are either acidic or basic. Amino acids are classified as
being either charged or neutral. This set is equivalent to the RasMol atom expressions acidic or basic and amino and not neutral.
Cyclic Set
The set of atoms in amino acids containing a cycle or rings. All amino acids are classified as either cyclic or acyclic. This set
consists of the amino acids His, Phe, Pro, Trp and Tyr. The members of the predefined set aromatic are members of this set. The
only cyclic but non-aromatic amino acid is proline. This set is equivalent to the RasMol atom expressions his, phe, pro, trp, tyr
and aromatic or pro and amino and not acyclic.
Cystine Set
This set contains the atoms of cysteine residues that form part of a disulphide bridge, i.e. half cystines. RasMol automatically
determines disulphide bridges, if neither the predefined set cystine nor the RasMol ssbonds command have been used since the mole-
cule was loaded. The set of free cysteines may be determined using the RasMol atom expression cys and not cystine.
Helix Set
This set contains all atoms that form part of a protein alpha helix as determined by either the PDB file author or Kabsch and
Sander's DSSP algorithm. By default, RasMol uses the secondary structure determination given in the PDB file if it exists. Other-
wise, it uses the DSSP algorithm as used by the RasMol structure command.
This predefined set should not be confused with the predefined set alpha which contains the alpha carbon atoms of a protein.
Hetero Set
This set contains all the heterogeneous atoms in the molecule. These are the atoms described by HETATM entries in the PDB file.
These typically contain water, cofactors and other solvents and ligands. All hetero atoms are classified as either ligand or solvent
atoms. These heterogeneous solvent atoms are further classified as either water or ions.
Hydrogen Set
This predefined set contains all the hydrogen, deuterium and tritium atoms of the current molecule. This predefined set is equiva-
lent to the RasMol atom expression elemno=1.
Hydrophobic Set
This set contains all the hydrophobic amino acids. These are the amino acids Ala, Leu, Val, Ile, Pro, Phe, Met and Trp. All amino
acids are classified as either hydrophobic or polar. This set is equivalent to the RasMol atom expressions ala, leu, val, ile, pro,
phe, met, trp and amino and not polar.
Ions Set
This set contains all the heterogeneous phosphate and sulphate ions in the current molecule data file. A large number of these ions
are sometimes associated with protein and nucleic acid structures determined by X-ray crystallography. These atoms tend to clutter
an image. All hetero atoms are classified as either ligand or solvent atoms. All solvent atoms are classified as either water or
ions.
Large Set
All amino acids are classified as either small, medium or large. This set is equivalent to the RasMol atom expression amino and not
(small or medium).
Ligand Set
This set contains all the heterogeneous cofactor and ligand moieties that are contained in the current molecule data file. This set
is defined to be all hetero atoms that are not solvent atoms. Hence this set is equivalent to the RasMol atom expression hetero and
not solvent.
Medium Set
All amino acids are classified as either small, medium or large. This set is equivalent to the RasMol atom expression amino and not
(large or small).
Neutral Set
The set of neutral amino acids. All amino acids are classified as either acidic, basic or neutral. This set is equivalent to the
RasMol atom expression amino and not (acidic or basic).
Nucleic Set
The set of all atoms in nucleic acids, which consists of the four nucleotide bases adenosine, cytidine, guanosine and thymidine (A,
C, G and T, respectively). All neucleotides are classified as either purine or pyrimidine. This set is equivalent to the RasMol
atom expressions a,c,g,t and purine or pyrimidine. The symbols for RNA nucleotides (U, +U, I, 1MA, 5MC, OMC, 1MG, 2MG, M2G, 7MG,
OMG, YG, H2U, 5MU, and PSU) are also recognized as members of this set.
Polar Set
This set contains the polar amino acids. All amino acids are classified as either hydrophobic or polar. This set is equivalent to
the RasMol atom expression amino and not hydrophobic.
Protein Set
The set of all atoms in proteins. This consists of the RasMol predefined set amino and common post-translation modifications.
Purine Set
The set of purine nucleotides. These are the bases adenosine and guanosine (A and G, respectively). All nucleotides are either
purines or pyrimidines. This set is equivalent to the RasMol atom expressions a,g and nucleic and not pyrimidine.
Pyrimidine Set
The set of pyrimidine nucleotides. These are the bases cytidine and thymidine (C and T, respectively). All nucleotides are either
purines or pyrimidines. This set is equivalent to the RasMol atom expressions c,t and nucleic and not purine.
Selected Set
This set contains the set of atoms in the currently selected region. The currently selected region is defined by the preceding
select or restrict command and not the atom expression containing the selected keyword.
Sheet Set
This set contains all atoms that form part of a protein beta sheet as determined by either the PDB file author or Kabsch and
Sander's DSSP algorithm. By default, RasMol uses the secondary structure determination given in the PDB file if it exists. Other-
wise, it uses the DSSP algorithm as used by the RasMol structure command.
Sidechain Set
This set contains the functional sidechains of any amino acids and the base of each nucleotide. These are the atoms not part of the
polypeptide N-C-C-O backbone of proteins or the sugar phosphate backbone of nucleic acids. Use the RasMol predefined sets protein
and nucleic to distinguish between the two forms of sidechain. Atoms in nucleic acids and proteins are either backbone or
sidechain. This set is equivalent to the RasMol expression (protein or nucleic) and not backbone.
Small Set
All amino acids are classified as either small, medium or large. This set is equivalent to the RasMol atom expression amino and not
(medium or large).
Solvent Set
This set contains the solvent atoms in the molecule coordinate file. These are the heterogeneous water molecules, phosphate and
sulphate ions. All hetero atoms are classified as either ligand or solvent atoms. All solvent atoms are classified as either water
or ions. This set is equivalent to the RasMol atom expressions hetero and not ligand and water or ions.
Surface Set
This set contains the atoms in those amino acids that tend (prefer) to be on the surface of proteins, in contact with solvent mole-
cules. This set refers to the amino acids preference and not the actual solvent accessibility for the current protein. All amino
acids are classified as either surface or buried. This set is equivalent to the RasMol atom expression amino and not buried.
Turn Set
This set contains all atoms that form part of a protein turns as determined by either the PDB file author or Kabsch and Sander's
DSSP algorithm. By default, RasMol uses the secondary structure determination given in the PDB file if it exists. Otherwise, it
uses the DSSP algorithm as used by the RasMol structure command.
Water Set
This set contains all the heterogeneous water molecules in the current database. A large number of water molecules are sometimes
associated with protein and nucleic acid structures determined by X-ray crystallography. These atoms tend to clutter an image. All
hetero atoms are classified as either ligand or solvent atoms. The solvent atoms are further classified as either water or ions.
Set Summary
The table below summarises RasMol's classification of the common amino acids.
COLOUR SCHEMES
The RasMol colour command allows different objects (such as atoms, bonds and ribbon segments) to be given a specified colour. Typically
this colour is either a RasMol predefined colour name or an RGB triple. Additionally RasMol also supports alt, amino, chain, charge, cpk,
group, model, shapely, structure, temperature or user colour schemes for atoms, and hbond type colour scheme for hydrogen bonds and elec-
trostatic potential colour scheme for dot surfaces. The 24 currently predefined colour names are Black, Blue, BlueTint, Brown, Cyan, Gold,
Grey, Green, GreenBlue, GreenTint, HotPink, Magenta, Orange, Pink, PinkTint, Purple, Red, RedOrange, SeaGreen, SkyBlue, Violet, White, Yel-
low and YellowTint
If you frequently wish to use a colour not predefined, you can write a one-line script. For example, if you make the file grey.col contain-
ing the line, colour [180,180,180] #grey, then the command script grey.col colours the currently selected atom set grey.
Alt Colours
The RasMol alt (Alternate Conformer) colour scheme codes the base structure with one colour and applies a limited number of colours
to each alternate conformer. In a RasMol built for 8-bit colour systems, 4 colours are allowed for alternate conformers. Otherwise,
8 colours are available.
Amino Colours
The RasMol amino colour scheme colours amino acids according to traditional amino acid properties. The purpose of colouring is to
identify amino acids in an unusual or surprising environment. The outer parts of a protein that are polar are visible (bright)
colours and non-polar residues darker. Most colours are hallowed by tradition. This colour scheme is similar to the shapely scheme.
Chain Colours
The RasMol chain colour scheme assigns each macromolecular chain a unique colour. This colour scheme is particularly useful for dis-
tinguishing the parts of multimeric structure or the individual 'strands' of a DNA chain. Chain can be selected from the RasMol
Colours menu.
Charge Colours
The RasMol charge colour scheme colour codes each atom according to the charge value stored in the input file (or beta factor field
of PDB files). High values are coloured in blue (positive) and lower values coloured in red (negative). Rather than use a fixed
scale this scheme determines the maximum and minimum values of the charge/temperature field and interpolates from red to blue appro-
priately. Hence, green cannot be assumed to be 'no net charge' charge.
The difference between the charge and temperature colour schemes is that increasing temperature values proceed from blue to red,
whereas increasing charge values go from red to blue.
If the charge/temperature field stores reasonable values it is possible to use the RasMol colour dots potential command to colour
code a dot surface (generated by the dots command) by electrostatic potential.
CPK Colours
The RasMol cpk colour scheme is based upon the colours of the popular plastic spacefilling models which were developed by Corey,
Pauling and later improved by Kultun. This colour scheme colours 'atom' objects by the atom (element) type. This is the scheme con-
ventionally used by chemists. The assignment of the most commonly used element types to colours is given below.
Group Colours
The RasMol group colour scheme colour codes residues by their position in a macromolecular chain. Each chain is drawn as a smooth
spectrum from blue through green, yellow and orange to red. Hence the N terminus of proteins and 5' terminus of nucleic acids are
coloured red and the C terminus of proteins and 3' terminus of nucleic acids are drawn in blue. If a chain has a large number of
heterogeneous molecules associated with it, the macromolecule may not be drawn in the full 'range' of the spectrum. Group can be
selected from the RasMol Colours menu.
If a chain has a large number of heterogeneous molecules associated with it, the macromolecule may not be drawn in the full range of
the spectrum. When RasMol performs group colouring it decides the range of colours it uses from the residue numbering given in the
PDB file. Hence the lowest residue number is displayed in blue and the highest residue number is displayed as red. Unfortunately, if
a PDB file contains a large number of heteroatoms, such as water molecules, that occupy the high residue numbers, the protein is
displayed in the blue-green end of the spectrum and the waters in the yellow-red end of the spectrum. This is aggravated by there
typically being many more water molecules than amino acid residues. The solution to this problem is to use the command set hetero
off before applying the group colour scheme. This can also be achieved by toggling Hetero Atoms on the Options menu before selecting
Group on the Colour menu. This command instructs RasMol to only use non-hetero residues in the group colour scaling.
NMR Model Colours
The RasMol model colour scheme codes each NMR model with a distinct colour. The NMR model number is taken as a numeric value. High
values are coloured in blue and lower values coloured in red. Rather than use a fixed scale this scheme determines the maximum value
of the NMR model number and interpolates from red to blue appropriately.
Shapely Colours
The RasMol shapely colour scheme colour codes residues by amino acid property. This scheme is based upon Bob Fletterick's "Shapely
Models". Each amino acid and nucleic acid residue is given a unique colour. The shapely colour scheme is used by David Bacon's
Raster3D program. This colour scheme is similar to the amino colour scheme.
Structure Colours
The RasMol structure colour scheme colours the molecule by protein secondary structure. Alpha helices are coloured magenta,
[240,0,128], beta sheets are coloured yellow, [255,255,0], turns are coloured pale blue, [96,128,255] and all other residues are
coloured white. The secondary structure is either read from the PDB file (HELIX, SHEET and TURN records), if available, or deter-
mined using Kabsch and Sander's DSSP algorithm. The RasMol structure command may be used to force DSSP's structure assignment to be
used.
Temperature Colours
The RasMol temperature colour scheme colour codes each atom according to the anisotropic temperature (beta) value stored in the PDB
file. Typically this gives a measure of the mobility/uncertainty of a given atom's position. High values are coloured in warmer
(red) colours and lower values in colder (blue) colours. This feature is often used to associate a "scale" value [such as amino acid
variability in viral mutants] with each atom in a PDB file, and colour the molecule appropriately.
The difference between the temperature and charge colour schemes is that increasing temperature values proceed from blue to red,
whereas increasing charge values go from red to blue.
User Colours
The RasMol user colour scheme allows RasMol to use the colour scheme stored in the PDB file. The colours for each atom are stored in
COLO records placed in the PDB data file. This convention was introduced by David Bacon's Raster3D program.
HBond Type Colours
The RasMol type colour scheme applies only to hydrogen bonds, hence is used in the command colour hbonds type. This scheme colour
codes each hydrogen bond according to the distance along a protein chain between hydrogen bond donor and acceptor. This schematic
representation was introduced by Belhadj-Mostefa and Milner-White. This representation gives a good insight into protein secondary
structure (hbonds forming alpha helices appear red, those forming sheets appear yellow and those forming turns appear magenta).
Potential Colours
The RasMol potential colour scheme applies only to dot surfaces, hence is used in the command colour dots potential. This scheme
colours each currently displayed dot by the electrostatic potential at that point in space. This potential is calculated using
Coulomb's law taking the temperature/charge field of the input file to be the charge assocated with that atom. This is the same
interpretation used by the colour charge command. Like the charge colour scheme low values are blue/white and high values are red.
Amino Acid Codes
The following table lists the names, single letter and three letter codes of each of the amino acids.
Booleans
A boolean parameter is a truth value. Valid boolean values are 'true' and 'false', and their synonyms 'on' and 'off'. Boolean param-
eters are commonly used by RasMol to either enable or disable a representation or option.
FILE FORMATS
Protein Data Bank Files
If you do not have the PDB documentation, you may find the following summary of the PDB file format useful. The Protein Data Bank is a com-
puter-based archival database for macromolecular structures. The database was established in 1971 by Brookhaven National Laboratory,
Upton, New York, as a public domain repository for resolved crystallographic structures. The Bank uses a uniform format to store atomic
coordinates and partial bond connectivities as derived from crystallographic studies. In 1999 the Protein Data Bank moved to the Research
Collaboratory for Structural Biology.
PDB file entries consist of records of 80 characters each. Using the punched card analogy, columns 1 to 6 contain a record-type identifier,
the columns 7 to 70 contain data. In older entries, columns 71 to 80 are normally blank, but may contain sequence information added by
library management programs. In new entries conforming to the 1996 PDB format, there is other information in those columns. The first four
characters of the record identifier are sufficient to identify the type of record uniquely, and the syntax of each record is independent of
the order of records within any entry for a particular macromolecule.
The only record types that are of major interest to the RasMol program are the ATOM and HETATM records which describe the position of each
atom. ATOM/HETATM records contain standard atom names and residue abbreviations, along with sequence identifiers, coordinates in Angstrom
units, occupancies and thermal motion factors. The exact details are given below as a FORTRAN format statement. The "fmt" column indicates
use of the field in all PDB formats, in the 1992 and earlier formats or in the 1996 and later formats.
Residues occur in order starting from the N-terminal residue for proteins and 5'-terminus for nucleic acids. If the residue sequence is
known, certain atom serial numbers may be omitted to allow for future insertion of any missing atoms. Within each residue, atoms are
ordered in a standard manner, starting with the backbone (N-C-C-O for proteins) and proceeding in increasing remoteness from the alpha car-
bon, along the side chain.
HETATM records are used to define post-translational modifications and cofactors associated with the main molecule. TER records are inter-
preted as breaks in the main molecule's backbone.
If present, RasMol also inspects HEADER, COMPND, HELIX, SHEET, TURN, CONECT, CRYST1, SCALE, MODEL, ENDMDL, EXPDTA and END records. Informa-
tion such as the name, database code, revision date and classification of the molecule are extracted from HEADER and COMPND records, ini-
tial secondary structure assignments are taken from HELIX, SHEET and TURN records, and the end of the file may be indicated by an END
record.
RasMol Interpretation of PDB fields
Atoms located at 9999.000, 9999.000, 9999.000 are assumed to be Insight pseudo atoms and are ignored by RasMol. Atom names beginning
' Q' are also assumed to be pseudo atoms or position markers.
When a data file contains an NMR structure, multiple conformations may be placed in a single PDB file delimited by pairs of MODEL
and ENDMDL records. RasMol displays all the NMR models contained in the file.
Residue names "CSH", "CYH" and "CSM" are considered pseudonyms for cysteine "CYS". Residue names "WAT", "H20", "SOL" and "TIP" are
considered pseudonyms for water "HOH". The residue name "D20" is consider heavy water "DOD". The residue name "SUL" is considered a
sulphate ion "SO4". The residue name "CPR" is considered to be cis-proline and is translated as "PRO". The residue name "TRY" is
considered a pseudonym for tryptophan "TRP".
RasMol uses the HETATM fields to define the sets hetero, water, solvent and ligand. Any group with the name "HOH", "DOD", "SO4" or
"PO4" (or aliased to one of these names by the preceding rules) is considered a solvent and is considered to be defined by a HETATM
field.
RasMol only respects CONECT connectivity records in PDB files containing fewer than 256 atoms. This is explained in more detail in
the section on determining molecule connectivity. CONECT records that define a bond more than once are interpreted as specifying the
bond order of that bond, i.e. a bond specified twice is a double bond and a bond specified three (or more) times is a triple bond.
This is not a standard PDB feature.
PDB Colour Scheme Specification
RasMol also accepts the supplementary COLO record type in the PDB files. This record format was introduced by David Bacon's Raster3D
program for specifying the colour scheme to be used when rendering the molecule. This extension is not currently supported by the
PDB. The COLO record has the same basic record type as the ATOM and HETATM records described above.
Colours are assigned to atoms using a matching process. The Mask field is used in the matching process as follows. First RasMol
reads in and remembers all the ATOM, HETATM and COLO records in input order. When the user-defined ('User') colour scheme is
selected, RasMol goes through each remembered ATOM/HETATM record in turn, and searches for a COLO record that matches in all of col-
umns 7 through 30. The first such COLO record to be found determines the colour and radius of the atom.
Note that the Red, Green and Blue components are in the same positions as the X, Y, and Z components of an ATOM or HETA record, and
the van der Waals radius goes in the place of the Occupancy. The Red, Green and Blue components must all be in the range 0 to 1.
In order that one COLO record can provide colour and radius specifications for more than one atom (e.g. based on residue, atom type,
or any other criterion for which labels can be given somewhere in columns 7 through 30), a 'don't-care' character, the hash mark "#"
(number or sharp sign) is used. This character, when found in a COLO record, matches any character in the corresponding column in a
ATOM/HETATM record. All other characters must match identically to count as a match. As an extension to the specification, any atom
that fails to match a COLO record is displayed in white.
Multiple NMR Models
RasMol loads all of the NMR models from a PDB file no matter which command is used: load pdb <filename> or load nmrpdb <filename>
Once multiple NMR conformations have been loaded they may be manipulated with the atom expression extensions described in Primitive
Expressions. In particular, the command restrict */1 will restrict the display to the first model only.
CIF and mmCIF Format Files
CIF is the IUCr standard for presentation of small molecules and mmCIF is intended as the replacement for the fixed-field PDB format
for presentation of macromolecular structures. RasMol can accept data sets in either format.
There are many useful sites on the World Wide Web where information tools and software related to CIF, mmCIF and the PDB can be
found. The following are good starting points for exploration:
The International Union of Crystallography (IUCr) provides access to software, dictionaries, policy statements and documentation
relating to CIF and mmCIF at: IUCr, Chester, England (www.iucr.org/iucr-top/cif/) with many mirror sites.
The Nucleic Acid Database Project provides access to its entries, software and documentation, with an mmCIF page giving access to
the dictionary and mmCIF software tools at Rutgers University, New Jersey, USA (http://ndbserver.rutgers.edu/NDB/mmcif) with many
mirror sites.
This version of RasMol restricts CIF or mmCIF tag values to essentially the same conventions as are used for the fixed-field PDB
format. Thus chain identifiers and alternate conformation identifiers are limited to a single character, atom names are limited to 4
characters, etc. RasMol interprets the following CIF and mmCIF tags: A search is made through multiple data blocks for the desired
tags, so a single dataset may be composed from multiple data blocks, but multiple data sets may not be stacked in the same file.
MACHINE-SPECIFIC SUPPORT
In the following sections, support for Monochrome X-Windows, Tcl/Tk IPC, UNIX sockets based IPC, Compiling RasWin with Borland and MetroW-
erks are described.
Monochrome X-Windows Support
RasMol supports the many monochrome UNIX workstations typically found in academia, such as low-end SUN workstations and NCD X-termi-
nals. The X11 version of RasMol (when compiled in 8 bit mode) now detects black and white X-Windows displays and enables dithering
automatically. The use of run-time error diffusion dithering means that all display modes of RasMol are available when in monochrome
mode. For best results, users should experiment with the set ambient command to ensure the maximum contrast in resulting images.
Tcl/Tk IPC support
Version 4 of Tk graphics library changed the protocol used to communicate between Tk applications. RasMol version 2.6 was modified
such that it could communicate with both this new protocol and the previous version 3 protocol supported by RasMol v2.5. Although
Tcl/Tk 3.x applications may only communicate with other 3.x applications and Tcl/Tk 4.x applications with other 4.x applications,
these changes allow RasMol to communicate between processes with both protocols (potentially concurrently).
UNIX sockets based IPC
The UNIX implementation of RasMol supports BSD-style socket communication. An identical socket mechanism is also being developed for
VMS, Apple Macintosh and Microsoft Windows systems. This should allow RasMol to interactively display results of a computation on a
remote host. The current protocol acts as a TCP/IP server on port 21069 that executes command lines until either the command exit or
the command quit is typed. The command exit from the RasMol server, the command quit both disconnects the current session and termi-
nates RasMol. This functionality may be tested using the UNIX command telnet <hostname> 21069.
Compiling RasWin with Borland and MetroWerks
A number of changes were made to the source code in the transition from version 2.5 to 2.6 to allow the Microsoft Windows version of
RasMol to compile using the Borland C/C++ compiler. These fixes include name changes for the standard library and special code to
avoid a bug in _fmemset. Additional changes were made in the transition from 2.6 to 2.7 to allow compilation with the MetroWerks
compilers.
BIBLIOGRAPHY
Molecular Graphics
[1] Nelson Max, "Computer Representation of Molecular Surfaces", IEEE Computer Graphics and Applications, pp.21-29, August 1983.
[2] Arthur M. Lesk, "Protein Architecture: A Practical Approach", IRL Press Publishers, 1991.
Molecular Graphics Programs
[3] Per J. Kraulis, "MOLSCRIPT: A Program to Produce both Detailed and Schematic Plots of Protein Structures", Journal of Applied Crystal-
lography, Vol.24, pp.946-950, 1991.
[4] David Bacon and Wayne F. Anderson, "A Fast Algorithm for Rendering Space-Filling Molecule Pictures", Journal of Molecular Graphics,
Vol.6, No.4, pp.219-220, December 1988.
[5] David C. Richardson and Jane S. Richardson, "The Kinemage: A tool for Scientific Communication", Protein Science, Vol.1, No.1,pp.3-9,
January 1992.
[6] Mike Carson, "RIBBONS 2.0", Journal of Applied Crystallography, Vol.24, pp.958-961, 1991.
[7] Conrad C. Huang, Eric F. Pettersen, Teri E. Klein, Thomas E. Ferrin and Robert Langridge, "Conic: A Fast Renderer for Space-Filling
Molecules with Shadows", Journal of Molecular Graphics, Vol.9, No.4, pp.230-236, December 1991.
Molecular Biology Algorithms
[8] Wolfgang Kabsch and Christian Sander, "Dictionary of Protein Secondary Structure: Pattern Recognition of Hydrogen-Bonded and Geometri-
cal Features", Biopolymers, Vol.22, pp.2577-2637, 1983.
[9] Michael L. Connolly, "Solvent-Accessible Surfaces of Proteins and Nucleic Acids", Science, Vol.221, No.4612, pp.709-713, August 1983.
[10] Khaled Belhadj-Mostefa, Ron Poet and E. James Milner-White, "Displaying Inter-Main Chain Hydrogen Bond Patterns in Proteins", Journal
of Molecular Graphics, Vol.9, No.3, pp.194-197, September 1991.
[11] Mike Carson, "Ribbon Models of Macromolecules", Journal of Molecular Graphics, Vol.5, No.2, pp.103-106, June 1987.
[12] Mike Carson and Charles E. Bugg, "Algorithm for Ribbon Models of Proteins", Journal of Molecular Graphics, Vol.4, No.2, pp.121-122,
June 1986.
[13] H. Iijima, J. B. Dunbar Jr. and G. Marshall, "Calibration of Effective van der Waals Atomic Contact Radii for Proteins and Peptides",
Proteins: Structure, Functions and Genetics, Vol.2, pp.330-339,1987.
Graphics Algorithms
[14] J. Foley, A. van Dam, S. Feiner and J. Hughes, "Computer Graphics: Principles and Practice", 2nd Edition, Addison Wesley Publishers,
1990.
[15] J. Cleary and G. Wyvill, "Analysis of an Algorithm for Fast Ray Tracing using Uniform Space Subdivision", The Visual Computer, Vol.4,
pp.65-83, 1988.
[16] Thomas Porter,"Spherical Shading", Computer Graphics Vol.12, ACM SIGGRAPH, pp.282-285, 1978.
[17] Jean-Michel Cense, "Exact Visibility Calculation for Space-Filling Molecular Models", Journal of Molecular Graphics, Vol.9, No.3,
pp.191-193, September 1991.
[18] Chris Schafmeister, "Fast Algorithm for Generating CPK Images on Graphics Workstations", Journal of Molecular Graphics, Vol.8, No.4,
pp.201-206, December 1990.
[19] Bruce A. Johnson, "MSURF: A Rapid and General Program for the Representation of Molecular Surfaces", Journal of Molecular Graphics,
Vol.5, No.3, pp.167-169, September 1987.
File Formats
[20] Frances C. Bernstein et al., "The Protein Data Bank: A Computer-Based Archival File for Macromolecular Structures", Journal of Molecu-
lar Biology, Vol.112, pp.535-542, 1977.
[21] Arthur Dalby, James G. Nourse, W. Douglas Hounshell, Ann K. I. Gushurst, David L. Grier, Burton A. Leland and John Laufer, "Descrip-
tion of Several Chemical File Formats Used by Computer Programs Developed at Molecular Design Limited", Journal of Chemical Information and
Computer Sciences, Vol.32, No.3, pp.244-255, 1992.
[22] Adobe Systems Inc., "PostScript Language Reference Manual", Addison-Wesley Publishers, Reading, Mass., 1985.
[23] Philip E. Bourne et al., "The Macromolecular Crystallographic Information File (mmCIF)", Meth. Enzymol. (1997) 277, 571-590.
[24] Sydney R. Hall, "The STAR File: a New Format for Electronic Data Transfer and Archiving", Journal of Chemical Information and Computer
Sciences, Vol. 31, 326-333, 1991.
SEE ALSO
The RasMol User Manual!
AUTHOR
1992-1998 by Roger Sayle (rasmol@ggr.co.uk)
July 2009 RASMOL(1)