N_FROZEN_CORE

Controls the number of frozen core orbitals.

TYPE:

INTEGER/STRING

DEFAULT:

0
No frozen core orbitals.

OPTIONS:

FC
Frozen core approximation.
$n$
Freeze $n$ core orbitals.

RECOMMENDATION:

There is no computational advantage to using frozen core for CIS, and
analytical derivatives are only available when no orbitals are frozen. It is
helpful when calculating CIS(D) corrections (see Sec. 7.8).

N_FROZEN_VIRTUAL

Controls the number of frozen virtual orbitals.

TYPE:

INTEGER

DEFAULT:

0
No frozen virtual orbitals.

OPTIONS:

$n$
Freeze $n$ virtual orbitals.

RECOMMENDATION:

There is no computational advantage to using frozen virtuals for CIS, and
analytical derivatives are only available when no orbitals are frozen.

MAX_CIS_CYCLES

Maximum number of CIS iterative cycles allowed.

TYPE:

INTEGER

DEFAULT:

30

OPTIONS:

$n$
User-defined number of cycles.

RECOMMENDATION:

Default is usually sufficient.

MAX_CIS_SUBSPACE

Maximum number of subspace vectors allowed in the CIS iterations

TYPE:

INTEGER

DEFAULT:

As many as required to converge all roots

OPTIONS:

$n$
User-defined number of subspace vectors

RECOMMENDATION:

The default is usually appropriate, unless a large number of states are
requested for a large molecule. The total memory required to store the
subspace vectors is bounded above by $2nOV$, where $O$ and $V$ represent the
number of occupied and virtual orbitals, respectively. $n$ can be reduced to
save memory, at the cost of a larger number of CIS iterations. Convergence may
be impaired if $n$ is not much larger than CIS_N_ROOTS.

CIS_CONVERGENCE

CIS is considered converged when error is less than ${10}^{-\mathrm{CIS}\mathrm{\_}\mathrm{CONVERGENCE}}$

TYPE:

INTEGER

DEFAULT:

6
CIS convergence threshold 10${}^{-6}$

OPTIONS:

$n$
Corresponding to ${10}^{-n}$

RECOMMENDATION:

None

CIS_DYNAMIC_MEM

Controls whether to use static or dynamic memory in CIS and TDDFT calculations.

TYPE:

LOGICAL

DEFAULT:

FALSE

OPTIONS:

FALSE
Partly use static memory
TRUE
Fully use dynamic memory

RECOMMENDATION:

The default control requires static memory (MEM_STATIC) to hold a
temporary array whose minimum size is $OV\times \text{CIS\_N\_ROOTS}$. For a
large calculation, one has to specify a large value for MEM_STATIC,
which is not recommended (see Chapter 2). Therefore, it is
recommended to use dynamic memory for large calculations.

CIS_RELAXED_DENSITY

Use the relaxed CIS density for attachment/detachment density analysis as well
as for for the general excited-state analysis of Section 10.2.6.

TYPE:

LOGICAL

DEFAULT:

FALSE

OPTIONS:

FALSE
Do not use the relaxed CIS density in analysis.
TRUE
Use the relaxed CIS density in analysis.

RECOMMENDATION:

None

CIS_GUESS_DISK

Read the CIS guess from disk (previous calculation).

TYPE:

LOGICAL

DEFAULT:

FALSE

OPTIONS:

FALSE
Create a new guess.
TRUE
Read the guess from disk.

RECOMMENDATION:

Requires a guess from previous calculation.

CIS_GUESS_DISK_TYPE

Determines the type of guesses to be read from disk

TYPE:

INTEGER

DEFAULT:

Nil

OPTIONS:

0
Read triplets only
1
Read triplets and singlets
2
Read singlets only

RECOMMENDATION:

Must be specified if CIS_GUESS_DISK is TRUE.

STS_MOM

Control calculation of the transition moments between excited states in the
CIS and TDDFT calculations (including SF-CIS and SF-DFT).

TYPE:

LOGICAL

DEFAULT:

FALSE

OPTIONS:

FALSE
Do not calculate state-to-state transition moments.
TRUE
Do calculate state-to-state transition moments.

RECOMMENDATION:

When set to true requests the state-to-state dipole transition moments for
all pairs of excited states and for each excited state with the ground
state.

Note: This option is not available for SF-XCIS.

CIS_MOMENTS

Controls calculation of excited-state (CIS or TDDFT) multipole moments.

TYPE:

LOGICAL

DEFAULT:

FALSE

OPTIONS:

FALSE
Do not calculate excited-state moments.
TRUE
Calculate moments for each excited state.

RECOMMENDATION:

Set to TRUE if excited-state moments are desired. (This is a trivial
additional calculation.) The MULTIPOLE_ORDER controls how many
multipole moments are printed.