In casman, the built-in methods can be run by simply setting the value of CORRELATION accordingly:
CORRELATION
CORRELATION
Sets the pre-defined method to use for casman.
TYPE:
STRING
DEFAULT:
None.
OPTIONS:
SF-CAS
CAS-SF with no perturbative corrections (or a custom method)
SF-CAS(h,p)
CAS-SF with perturbative corrections for hole (h) and particle (p) excitations
SF-CAS(S)
CAS-SF with perturbative corrections for single (h,p,hp) excitations
SF-CAS(2x)
CAS-SF with perturbative corrections for 2x (h,p,hp,hh,pp) excitations
SF-CAS(3x)
CAS-SF with perturbative corrections for 3x (h,p,hp,hh,pp,hhp,hpp) excitations
SF-CAS(3x)+D
CAS-SF with perturbative corrections for (h,p,hp,hh,pp,hhp,hpp) + MP2 RAS1 RAS3 double excitations
RECOMMENDATION:
None.
If a custom excitation scheme is required, one can set CORRELATION = SF-CAS and set the following variables manually. (If you are using one of the built-in methods, setting these variables manually should be avoided, since they are automatically set up appropriately by Q-Chem if CORRELATION is not SF-CAS.)
RAS_N_SPIN_FLIP
RAS_N_SPIN_FLIP
Sets the number of spin-flips.
TYPE:
INTEGER
DEFAULT:
Maximum number of spin-flips ()
OPTIONS:
Do spin-flips
RECOMMENDATION:
None.
CAS_DO_NDPT
CAS_DO_NDPT
Do non-degenerate perturbation theory?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do non-degenerate perturbation theory.
FALSE
Do not use non-degenerate perturbation theory.
RECOMMENDATION:
None.
CAS_QDPT_ORDER
CAS_QDPT_ORDER
Order of terms kept in the quasi-degenerate perturbation theory denominator expansion.
TYPE:
INTEGER
DEFAULT:
None.
OPTIONS:
Keep terms of order in the denominator expansion.
RECOMMENDATION:
None.
CAS_DO_1X
CAS_DO_1X
Do perturbative hole (h) and particle (p) correction?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do perturbative hole (h) and particle (p) correction
FALSE
Do not do perturbative hole (h) and particle (p) correction
RECOMMENDATION:
None.
CAS_DO_SINGLES
CAS_DO_SINGLES
Do perturbative singles (h,p,hp) correction?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do perturbative singles correction
FALSE
Do not do perturbative singles correction
RECOMMENDATION:
None.
CAS_DO_2x
CAS_DO_2x
Do perturbative 2x (h,p,hp,hh,pp) correction?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do perturbative 2x correction
FALSE
Do not do perturbative 2x correction
RECOMMENDATION:
None.
CAS_DO_3x
CAS_DO_3x
Do perturbative 3x (h,p,hp,hh,pp,hhp,hpp) correction?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do perturbative 3x correction
FALSE
Do not do perturbative 3x correction
RECOMMENDATION:
None.
CAS_DO_DOUBLES
CAS_DO_DOUBLES
Do perturbative (h,p,hp,hh,pp,hhp,hpp) correction + MP2 RAS1 RAS3 doubles?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Do perturbative (h,p,hp,hh,pp,hhp,hpp) + MP2 RAS1 RAS3 doubles correction
FALSE
Do not do the correction
RECOMMENDATION:
None.
CAS_LEVEL_SHIFT
CAS_LEVEL_SHIFT
Use a denominator level-shift?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Use the denominator level-shift
FALSE
Do not use the denominator level-shift
RECOMMENDATION:
None.
CAS_SPARSE
CAS_SPARSE
Use a sparse matrix multiply when forming the effective Hamiltonian?
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
TRUE
Use sparse matrix multiply in forming effective Hamiltonian
FALSE
Do not use sparse matrix multiply in forming effective Hamiltonian
RECOMMENDATION:
None. Can be useful for larger numbers of spin-flips.