7.2 Uncorrelated Wave Function Methods

7.2.7 Basic CIS Job Control Options

(May 16, 2021)

CIS-type jobs are requested by setting the $rem variable EXCHANGE = HF and CORRELATION = NONE, as in a ground-state Hartree-Fock calculation, but then also specifying a number of excited-state roots using the $rem keyword CIS_N_ROOTS.

Note:  For RHF case, n singlets and n triplets will be computed, unless specified otherwise by using CIS_TRIPLETS and CIS_SINGLETS.

CIS_N_ROOTS
       Sets the number of CI-Singles (CIS) excited state roots to find.
TYPE:
       INTEGER
DEFAULT:
       0 Do not look for any excited states.
OPTIONS:
       n n>0 Looks for n CIS excited states.
RECOMMENDATION:
       None

CIS_SINGLETS
       Solve for singlet excited states in RCIS calculations (ignored for UCIS).
TYPE:
       LOGICAL
DEFAULT:
       TRUE
OPTIONS:
       TRUE Solve for singlet states. FALSE Do not solve for singlet states.
RECOMMENDATION:
       None

CIS_TRIPLETS
       Solve for triplet excited states in RCIS calculations (ignored for UCIS).
TYPE:
       LOGICAL
DEFAULT:
       TRUE
OPTIONS:
       TRUE Solve for triplet states. FALSE Do not solve for triplet states.
RECOMMENDATION:
       None

RPA
       Do an RPA calculation in addition to a CIS or TDDFT/TDA calculation.
TYPE:
       LOGICAL/INTEGER
DEFAULT:
       FALSE
OPTIONS:
       FALSE Do not do an RPA calculation. TRUE Do an RPA calculation. 2 Do an RPA calculation without running CIS or TDDFT/TDA first.
RECOMMENDATION:
       None

CIS_STATE_DERIV
       Sets CIS state for excited state optimizations and vibrational analysis.
TYPE:
       INTEGER
DEFAULT:
       0 Does not select any of the excited states.
OPTIONS:
       n Select the nth state.
RECOMMENDATION:
       Check to see that the states do not change order during an optimization, due to state crossings.

SPIN_FLIP
       Selects whether to perform a standard excited state calculation, or a spin-flip calculation. Spin multiplicity should be set to 3 for systems with an even number of electrons, and 4 for systems with an odd number of electrons.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       TRUE/FALSE
RECOMMENDATION:
       None

SPIN_FLIP_XCIS
       Do a SF-XCIS calculation.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE Do not do an SF-XCIS calculation. TRUE Do an SF-XCIS calculation (requires ROHF triplet ground state).
RECOMMENDATION:
       None

SFX_AMP_OCC_A
       Defines a custom amplitude guess vector in SF-XCIS method.
TYPE:
       INTEGER
DEFAULT:
       0
OPTIONS:
       n builds a guess amplitude with an α-hole in the nth orbital (requires SFX_AMP_VIR_B).
RECOMMENDATION:
       Only use when default guess is not satisfactory.

SFX_AMP_VIR_B
       Defines a user-specified amplitude guess vector in SF-XCIS method.
TYPE:
       INTEGER
DEFAULT:
       0
OPTIONS:
       n builds a guess amplitude with a β-particle in the nth orbital (requires SFX_AMP_OCC_A).
RECOMMENDATION:
       Only use when default guess is not satisfactory.

XCIS
       Do an XCIS calculation in addition to a CIS calculation.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE Do not do an XCIS calculation. TRUE Do an XCIS calculation (requires ROHF ground state).
RECOMMENDATION:
       None

SASF_RPA
       Do an SA-SF-CIS/DFT calculation.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE Do not do an SA-SF-CIS/DFT calculation. TRUE Do an SA-SF-CIS/DFT calculation (requires ROHF ground state).
RECOMMENDATION:
       None