10.14 General Response Theory

10.14.1 Job Control

(May 16, 2021)

Only one keyword is necessary in the $rem section to activate the response module. All other options are controlled through the $response input section.

RESPONSE
       Activate the general response property module.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE (or 0) Don’t activate the general response property module. TRUE (or 1) Activate the general response property module.
RECOMMENDATION:
       None.

ORDER
       Sets the maximum order of response theory to perform.
INPUT SECTION: $response
TYPE:
       STRING
DEFAULT:
       LINEAR
OPTIONS:
       LINEAR Perform up through linear response.
RECOMMENDATION:
       None. Currently, only linear response is implemented.

SOLVER
       Sets the algorithm for solving the response equations.
INPUT SECTION: $response
TYPE:
       STRING
DEFAULT:
       DIIS
OPTIONS:
       LINEAR Iteratively solve the response equations without convergence acceleration. DIIS Iteratively solve the response equations using DIIS for convergence acceleration.
RECOMMENDATION:
       DIIS

HAMILTONIAN
       Sets the approximation used for the orbital Hessian.
INPUT SECTION: $response
TYPE:
       STRING
DEFAULT:
       RPA
OPTIONS:
       RPA No approximations. TDA Same as the CIS approximation. CIS Synonym for TDA.
RECOMMENDATION:
       None.

SPIN
       Does the operator access same spin (singlet) or different spin (triplet) states?
INPUT SECTION: $response
TYPE:
       STRING
DEFAULT:
       SINGLET
OPTIONS:
       SINGLET Operator is spin-conserving. TRIPLET Operator is not spin-conserving.
RECOMMENDATION:
       None. Care must be taken as all operators in a single calculation will be forced to follow this option.

MAXITER
       Maximum number of iterations.
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       60
OPTIONS:
       n Maximum number of iterations.
RECOMMENDATION:
       Use the default value.

CONV
       Convergence threshold. For the DIIS solver, this is the DIIS error norm. For the linear solver, this is the response vector RMSD between iterations.
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       8
OPTIONS:
       n Sets the convergence threshold to 10-n.
RECOMMENDATION:
       Use the default value.

DIIS_START
       Iteration number to start DIIS. Before this, linear iterations are performed.
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       1
OPTIONS:
       n Iteration number to start DIIS.
RECOMMENDATION:
       Use the default value.

DIIS_VECTORS
       Maximum number of DIIS vectors to keep.
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       7
OPTIONS:
       n>0 Maximum number of DIIS vectors to keep.
RECOMMENDATION:
       Use the default value.

RHF_AS_UHF
       Should the response equations be solved as though an unrestricted reference is being used?
INPUT SECTION: $response
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       TRUE Treat an RHF wavefunction as though it were UHF. FALSE Treat an RHF wavefunction as RHF.
RECOMMENDATION:
       Use the default value. Only useful for debugging.

PRINT_LEVEL
       Sets a general printing level across the response module.
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       2
OPTIONS:
       1 Print the initial guess and the final results. 2 1 + iterations and comments. 10 Kill trees.
RECOMMENDATION:
       Use the default value.

RUN_TYPE
       Should a single response calculation be performed, or should all permutations of the orbital Hessian and excitation type be performed?
INPUT SECTION: $response
TYPE:
       STRING
DEFAULT:
       SINGLE
OPTIONS:
       SINGLE Use only the orbital Hessian and excitation type specified in their respective keywords. ALL Use all permutations of RPA/TDA and singlet/triplet.
RECOMMENDATION:
       Use the default value, unless a comparison between approximations and excitation types is desired.

SAVE
       Save any quantities to disk?
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       0
OPTIONS:
       0 Don’t save any quantities to disk. 1 Save quantities in MO basis. 2 Save quantities in MO and AO bases.
RECOMMENDATION:
       None.

READ
       Read any quantities from disk?
INPUT SECTION: $response
TYPE:
       INTEGER
DEFAULT:
       0
OPTIONS:
       0 Don’t read any quantities from disk. 1 Read quantities in MO basis. 2 Read quantities in AO basis.
RECOMMENDATION:
       None.

DUMP_AO_INTEGRALS
       Should AO-basis property integrals be saved to disk?
INPUT SECTION: $response
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       TRUE Save AO-basis property integrals to disk. FALSE Don’t save AO-basis property integrals to disk.
RECOMMENDATION:
       None.

FORCE_NOT_NONORTHOGONAL
       Should the canonical response equations be solved, ignoring the identity of the underlying orbitals?
INPUT SECTION: $response
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       TRUE FALSE
RECOMMENDATION:
       Leave as false. Using the standard (canonical) response equations with non-orthogonal MOs will give incorrect results.

FORCE_NONORTHOGONAL
       Should the non-orthogonal response equations be solved, ignoring the identity of the underlying orbitals?
INPUT SECTION: $response
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       TRUE FALSE
RECOMMENDATION:
       Leave as false. When used with canonical MOs, this should give the same answer as with the standard equations, but at greater computational cost.

FREQUENCY
       Strength of one or more incident fields in atomic units. A separate response calculation will be performed for every field strength. 0.0 corresponds to the static limit.
INPUT SECTION: $response
TYPE:
       DOUBLE
DEFAULT:
       0.0
OPTIONS:
       lmn One or more field strengths separated by spaces.
RECOMMENDATION:
       None.