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# 7.9.7 RI-CIS(D), SOS-CIS(D), and SOS-CIS(D${}_{0}$): Job Control

(February 4, 2022)

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 7.2.2. 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

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${}_{0}$)
RECOMMENDATION:
None

CIS_N_ROOTS

CIS_N_ROOTS
Sets the number of excited state roots to find
TYPE:
INTEGER
DEFAULT:
0 Do not look for any excited states
OPTIONS:
$n$ $n>0$ Looks for $n$ excited states
RECOMMENDATION:
None

CIS_SINGLETS

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

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

SET_STATE_DERIV
Sets the excited state index for analytical gradient calculation for geometry optimizations and vibrational analysis with SOS-CIS(D${}_{0}$)
TYPE:
INTEGER
DEFAULT:
0
OPTIONS:
$n$ Select the $n$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

MEM_STATIC
Sets the memory for individual program modules
TYPE:
INTEGER
DEFAULT:
64 corresponding to 64 MB
OPTIONS:
$n$ User-defined number of megabytes.
RECOMMENDATION:
At least $150(N^{2}+N)D$ of MEM_STATIC is required ($N$: number of basis functions, $D$: size of a double precision storage, usually 8). Because a number of matrices with $N^{2}$ size also need to be stored, 32–160 MB of additional MEM_STATIC is needed.

MEM_TOTAL

MEM_TOTAL
Sets the total memory available to Q-Chem
TYPE:
INTEGER
DEFAULT:
2000 2 GB
OPTIONS:
$n$ User-defined number of megabytes
RECOMMENDATION:
The minimum memory requirement of RI-CIS(D) is approximately MEM_STATIC + max$(3SVXD,3X^{2}D)$ ($S$: number of excited states, $X$: number of auxiliary basis functions, $D$: 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${}_{0}$) is approximately MEM_STATIC + $20X^{2}D$. SOS-CIS(D${}_{0}$) gradient calculation becomes more efficient when $30X^{2}D$ 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

SOS_FACTOR
Sets the scaling parameter $c_{T}$
TYPE:
INTEGER
DEFAULT:
1300000 corresponding to 1.30
OPTIONS:
$n$ $c_{T}=n/1000000$
RECOMMENDATION:
Use the default

SOS_UFACTOR

SOS_UFACTOR
Sets the scaling parameter $c_{U}$
TYPE:
INTEGER
DEFAULT:
151 For SOS-CIS(D), corresponding to 1.51 140 For SOS-CIS(D${}_{0}$), corresponding to 1.40
OPTIONS:
$n$ $c_{U}=n/100$
RECOMMENDATION:
Use the default