table of contents
optking(1) | optking(1) |
cceom - equation of motion coupled cluster energy
program
DESCRIPTION
The program cceom calculates EOM-CCSD energies using a Davidson algorithm
to solve for the right-hand eigenvectors of the CC Hamiltonian.
COMMAND LINE ARGUMENTS
After internal coordinates are detected or generated, optking will enter a
run-time mode dependent on command line arguments.
REFERENCES
--dot_with_Lg - check the orthogonality of the excited right-hand eigenvector with - the ground state left eigenvector, lambda. cclambda must be run - first for this to work
- 1.
- The equation of motion coupled-cluster method. A systematic
biorthogonal approach to molecular excitation energies, transition
probabilities, and excited state properties, J. F. Stanton and R. J.
Bartlett, J. Chem. Phys. 98, 7029 (1993).
- EOM_REFERENCE = integer
- specifies the algorithm used by cceom. useful for
debugging. also must currently be set to ROHF, if you want to get triplet
excited states from a singlet ground state. The default is whatever
"REFERENCE" is.
- STATES_PER_IRREP = array of integers
- specifies the number of states of each irreducible
representation desired. For example, in C2v symmetry, (0 2 0 0) specifies
two excited states of A2 symmetry to be solved, regardless of the symmetry
of the ground state.
- PROP_SYM = integer
- specifies the symmetry of the state that should be used to
compute properties. defaults to the last irrep for which states are
requested.
- PROP_ROOT = integer
- specifies the number of the root (within its irrep) that
should be used to compute properties. defaults to the highest root
requested.
- EXCITATION_RANGE = excitation_range
- used to generate initial guesses. the larger the value, the
more initial guesses are made in the Davidson algorithm.
- RESIDUAL_TOL = integer
- Davidson algorithm will converge until the norm of the
residual vector is less than 10^(-integer). default if 4.
- EVAL_TOL = integer
- Davidson algorithm will converge until the change in the
excitation energy is less than 10^(-integer). default if 6.
Sept 2002 |