These methods are activated by setting the $rem keyword METHOD to RICIS(D), SOSCIS(D), and SOSCIS(D0), respectively. Other keywords are the same as in CIS method explained in Section 7.2.1. As these methods rely on the RI approximation, AUX_BASIS needs to be set by following the same guide as in RI-MP2 (Section 6.6).
METHOD
Excited state method of choice
TYPE:
STRING
DEFAULT:
None
OPTIONS:
RICIS(D)
Activate RI-CIS(D)
SOSCIS(D)
Activate SOS-CIS(D)
SOSCIS(D0)
Activate SOS-CIS(D)
RECOMMENDATION:
None
CIS_N_ROOTS
Sets the number of excited state roots to find
TYPE:
INTEGER
DEFAULT:
0
Do not look for any excited states
OPTIONS:
Looks for excited states
RECOMMENDATION:
None
CIS_SINGLETS
Solve for singlet excited states (ignored for spin unrestricted systems)
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 (ignored for spin unrestricted systems)
TYPE:
LOGICAL
DEFAULT:
TRUE
OPTIONS:
TRUE
Solve for triplet states
FALSE
Do not solve for triplet states.
RECOMMENDATION:
None
SET_STATE_DERIV
Sets the excited state index for analytical gradient calculation
for geometry optimizations and vibrational analysis with SOS-CIS(D)
TYPE:
INTEGER
DEFAULT:
0
OPTIONS:
Select the th state.
RECOMMENDATION:
Check to see that the states do no change order during an optimization.
For closed-shell systems, either CIS_SINGLETS or CIS_TRIPLETS
must be set to false.
MEM_STATIC
Sets the memory for individual program modules
TYPE:
INTEGER
DEFAULT:
64
corresponding to 64 MB
OPTIONS:
User-defined number of megabytes.
RECOMMENDATION:
At least of MEM_STATIC is required
(: number of basis functions, : size of a double precision storage, usually 8).
Because a number of matrices with size also need to be
stored, 32–160 MB of additional MEM_STATIC is needed.
MEM_TOTAL
Sets the total memory available to Q-Chem
TYPE:
INTEGER
DEFAULT:
2000
2 GB
OPTIONS:
User-defined number of megabytes
RECOMMENDATION:
The minimum memory requirement of RI-CIS(D) is approximately
MEM_STATIC + max
(: number of excited states, : number of auxiliary basis
functions, : size of a double precision storage, usually 8). However, because
RI-CIS(D) uses a batching scheme for efficient evaluations of electron
repulsion integrals, specifying more memory will significantly speed up the
calculation. Put as much memory as possible if you are not sure
what to use, but never put any more than what is available.
The minimum memory requirement of SOS-CIS(D) and SOS-CIS(D) is approximately
MEM_STATIC + . SOS-CIS(D) gradient calculation
becomes more efficient when more memory space is given.
Like in RI-CIS(D), put as much memory as possible if you are not sure what to use.
The actual memory size used in these calculations will be printed out in the output file
to give a guide about the required memory.
SOS_FACTOR
Sets the scaling parameter
TYPE:
INTEGER
DEFAULT:
1300000
corresponding to 1.30
OPTIONS:
RECOMMENDATION:
Use the default
SOS_UFACTOR
Sets the scaling parameter
TYPE:
INTEGER
DEFAULT:
151
For SOS-CIS(D), corresponding to 1.51
140
For SOS-CIS(D), corresponding to 1.40
OPTIONS:
RECOMMENDATION:
Use the default