CCEOM¶
Performs equation-of-motion (EOM) coupled cluster excited state computations.
General¶
CACHELEVEL¶
Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g.,
integrals) may be held in the cache.
- Type: integer
- Default: 2
CACHETYPE¶
The criterion used to retain/release cached data
- Type: string
- Possible Values: LOW, LRU
- Default: LRU
CC3_FOLLOW_ROOT¶
Do turn on root following for CC3
- Type: boolean
- Default: false
CC_NUM_THREADS¶
Number of threads
- Type: integer
- Default: 1
COLLAPSE_WITH_LAST¶
Do collapse with last vector?
- Type: boolean
- Default: true
COMPLEX_TOLERANCE¶
Complex tolerance applied in CCEOM computations
- Type: conv double
- Default: 1e-12
EOM_GUESS¶
Specifies a set of single-excitation guess vectors for the EOM-CC procedure. If EOM_GUESS = SINGLES, the guess will be taken from the singles-singles block of the similarity-transformed Hamiltonian, Hbar. If EOM_GUESS = DISK, guess vectors from a previous computation will be read from disk. If EOM_GUESS = INPUT, guess vectors will be specified in user input. The latter method is not currently available.
- Type: string
- Possible Values: SINGLES, DISK, INPUT
- Default: SINGLES
EOM_REFERENCE¶
Reference wavefunction type for EOM computations
- Type: string
- Possible Values: RHF, ROHF, UHF
- Default: RHF
E_CONVERGENCE¶
Convergence criterion for excitation energy (change) in the Davidson algorithm for CC-EOM. See Table Post-SCF Convergence for default convergence criteria for different calculation types.
- Type: conv double
- Default: 1e-8
FULL_MATRIX¶
Do use full effective Hamiltonian matrix?
- Type: boolean
- Default: false
LOCAL_CUTOFF¶
Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).
- Type: double
- Default: 0.02
LOCAL_DO_SINGLES¶
- Type: boolean
- Default: true
LOCAL_FILTER_SINGLES¶
Do apply local filtering to singles amplitudes?
- Type: boolean
- Default: true
LOCAL_GHOST¶
Permit ghost atoms to hold projected atomic orbitals to include in the virtual space in local-EOM-CCSD calculations
- Type: integer
- Default: -1
LOCAL_METHOD¶
Type of local-CCSD scheme to be simulated. WERNER selects the method developed by H.-J. Werner and co-workers, and AOBASIS selects the method developed by G.E. Scuseria and co-workers (currently inoperative).
- Type: string
- Possible Values: WERNER, AOBASIS
- Default: WERNER
LOCAL_PRECONDITIONER¶
Preconditioner will be used in local CC computations
- Type: string
- Possible Values: HBAR, FOCK
- Default: HBAR
LOCAL_WEAKP¶
Desired treatment of “weak pairs” in the local-CCSD method. A value of NEGLECT ignores weak pairs entirely. A value of NONE treats weak pairs in the same manner as strong pairs. A value of MP2 uses second-order perturbation theory to correct the local-CCSD energy computed with weak pairs ignored.
- Type: string
- Possible Values: NONE, MP2, NEGLECT
- Default: NONE
NEW_TRIPLES¶
Do use new triples?
- Type: boolean
- Default: true
NUM_AMPS_PRINT¶
Number of important CC amplitudes to print
- Type: integer
- Default: 5
PROP_ROOT¶
Root number (within its irrep) for computing properties. Defaults to highest root requested.
- Type: integer
- Default: 0
PROP_SYM¶
Symmetry of the state to compute properties. Defaults to last irrep for which states are requested.
- Type: integer
- Default: 1
RESTART_EOM_CC3¶
Do restart from on-disk?
- Type: boolean
- Default: false
RHF_TRIPLETS¶
Do form a triplet state from RHF reference?
- Type: boolean
- Default: false
ROOTS_PER_IRREP¶
Number of excited states per irreducible representation for EOM-CC and CC-LR calculations. Irreps denote the final state symmetry, not the symmetry of the transition.
- Type: array
- Default: No Default
R_CONVERGENCE¶
Convergence criterion for norm of the residual vector in the Davidson algorithm for CC-EOM.
- Type: conv double
- Default: 1e-6
SCHMIDT_ADD_RESIDUAL_TOLERANCE¶
Minimum absolute value above which a guess vector to a root is added to the Davidson algorithm in the EOM-CC iterative procedure.
- Type: conv double
- Default: 1e-3
SEMICANONICAL¶
Convert ROHF MOs to semicanonical MOs
- Type: boolean
- Default: true
SINGLES_PRINT¶
Do print information on the iterative solution to the single-excitation EOM-CC problem used as a guess to full EOM-CC?
- Type: boolean
- Default: false
SS_E_CONVERGENCE¶
Convergence criterion for excitation energy (change) in the Davidson algorithm for the CIS guess to CC-EOM.
- Type: conv double
- Default: 1e-6
SS_R_CONVERGENCE¶
Convergence criterion for norm of the residual vector in the Davidson algorithm for the CIS guess to CC-EOM.
- Type: conv double
- Default: 1e-6
SS_SKIP_DIAG¶
Do skip diagonalization of Hbar SS block?
- Type: boolean
- Default: false
SS_VECS_PER_ROOT¶
SS vectors stored per root
- Type: integer
- Default: 5
T3_WS_INCORE¶
Do build W intermediates required for eom_cc3 in core memory?
- Type: boolean
- Default: false
VECS_PER_ROOT¶
Vectors stored per root
- Type: integer
- Default: 12
Expert¶
EXCITATION_RANGE¶
The depth into the occupied and valence spaces from which one-electron excitations are seeded into the Davidson guess to the CIS (the default of 2 includes all single excitations between HOMO-1, HOMO, LUMO, and LUMO+1). This CIS is in turn the Davidson guess to the EOM-CC. Expand to capture more exotic excited states in the EOM-CC calculation
- Type: integer
- Default: 2