detcasman(1) [debian man page]
detcasman(1) detcasman(1) NAME
detcasman - Determinant Configuration Interaction / Complete Active Space Self-Consistent-Field Program Manager DESCRIPTION
The program detcasman manages the orbital optimization in a complete-active-space self-consistent field (CASSCF) procedure. It is a very simple program that runs the integral transformation, CI calculation, Lagrangian, and orbital rotation modules that work with the DETCI program. The real work of orbital optimization is done in the program detcas. FILES REQUIRED
input.dat - Input file FILES UPDATED
output.dat - Output file INPUT FORMAT
NCASITER = integer The number of orbital optimization iterations to be carried out. The driver will stop when this many iterations have been com- pleted, or earlier if convergence has been achieved. The default value is 30. See the man pages for DETCI and DETCAS for setting the convergence criteria. SCALE_CONV = double The scale factor to be used to determine the CI convergence from the previous iteration's orbital convergence. We take the smaller of the scaled and unscaled orbital gradients, and multiply this by the scale factor to determine the CI vector convergence. The default is 0.01. 8 Oct, 1998 detcasman(1)
Check Out this Related Man Page
stable(1) stable(1) NAME
stable - MO Hessian stability analysis program DESCRIPTION
The program stable performs a stability analysis on the molecular orbitals by diagonalizing the molecular orbital Hessian. The analysis includes orbital rotations which may break spin or spatial symmetry. If an instability is detected (i.e., there are negative eigenvalues of the MO Hessian), the previous Hartree-Fock self consistent field (SCF) computation has landed on a local minimum, not the global mini- mum, in orbital rotation space. For spatial- or symmetry-breaking rotations, this merely means that there is another orbital occupation or a UHF wavefunction with a lower energy. For instabilties which preserve the reference type (RHF or UHF) and are totally symmetric, this suggests that the SCF computation has simply found the wrong solution and should be re-run using a new initial guess. Instabilities corresponding to spatial symmetry breaking rotatios can be resolved by re-running the calculation in a lower computational point group. (It may also be necessary to employ some trick to break the symmetry of the initial guess wavefunction). Instabilities cor- responding to spin symmetry breaking rotations (RHF->UHF) can be resolved by re-running the SCF using a UHF reference. For UHF wavefunctions with totally-symmetric instabilities, it is possible to follow the instability automatically toward the global mini- mum by setting FOLLOW=TRUE. INPUT FORMAT
Input for this program is read from the file The following keywords are valid: CACHELEV = integer This is the cache level used for the DPD files. It functions the same way as in the coupled-cluster codes. Currently, this is hardwired to 0. FOLLOW = boolean If TRUE, then the eigenvector corresponding to the most negative eigenvalue of the MO Hessian will be followed to try to find a lower energy Hartree-Fock solution. The orbitals will be rotated, and the cscf module should be re-run using these new guess orbitals. NUM_EVECS_PRINT = integer Gives the number of MO Hessian eigenvectors to print. PRINT = integer The print level determines how much information is printed by the program. Values typically range from 1 (minimal printing) to 5 (very verbose printing for debugging only). The default is 1. REFERENCE = string This is the reference type, RHF, ROHF, or UHF. The default is RHF. SCALE = real This is the scale factor used for taking steps in eigenvector following. Normal values would be between 0 and 1. The default is 0.5. 23 Aug, 2003 stable(1)