NOCIS, 1C-NOCIS, and STEX run as subroutines in GEN_SCFMAN. Thus, for all calculations, you must set GEN_SCFMAN = TRUE. It is also highly recommended that you run an open-shell ground state calculation prior to running your NOCIS/STEX/1C-NOCIS calculations, which are all restricted.
NOCIS
NOCIS
Requests a NOCIS/STEX/1C-NOCIS/EA-TDDFT calculation.
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
FALSE
Do not run these methods.
TRUE
Run one of these methods, options controlled in $nocis.
RECOMMENDATION:
None
Options below this line are set within the $nocis section.
STEX
Run a STEX calculation
INPUT SECTION: $nocis
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
The presence of this keyword will activate STEX.
RECOMMENDATION:
None
ONE_CENTER
Run a 1C-NOCIS calculation
INPUT SECTION: $nocis
TYPE:
LOGICAL
DEFAULT:
FALSE
OPTIONS:
False
Run a NOCIS calculation.
True
Run a 1C-NOCIS calculation.
RECOMMENDATION:
None
ORB_OFFSET
Determines the starting orbital for a NOCIS/STEX/1C-NOCIS/EA-TDDFT calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
NONE
OPTIONS:
Positive integer
RECOMMENDATION:
Set according to the first orbital of interest in the system in question.
For example, this would be set to 0 for the O K-edge in CO because
the two O 1s orbitals lie below the C 1s, so for the C K-edge this
would be set to 2.
NUM_REF
Sets the number of reference orbitals in a NOCIS/STEX/1C-NOCIS/EA-TDDFT calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
NONE
OPTIONS:
Positive integer
RECOMMENDATION:
Set according to the number of consecutive orbitals of interest for the
calculation. For example, for the oxygen K-edge in CO, the
number of references would be 2 (two O 1s orbitals),
whereas for the carbon K-edge it would be 1 (one C 1s).
Options below this line are exclusive to 1C-NOCIS calculations for 2eOS references.
OS_IS
Triggers a 1C-NOCIS calculation with an M = 0 open-shell initial state (IS).
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
ROKS
OPTIONS:
CIS
Employ a CIS excited-state wave function transformed into the NTO basis as the IS
ROKS
Employ a ROKS- or ROHF-optimized wave function (singlets or triplets) as the IS
CIS_ROKS
Use CIS NTOs as a guess for an RO calculation on the IS.
RECOMMENDATION:
Use CIS when targeting a well-defined initial state. Else use ROSCF. Note that,
if the CIS_ROKS option is used, the previous excited state job can employ TDDFT instead
of CIS to provide a better guess.
OS_IS_CIS_STATE
When using CIS or CIS_ROKS for OS_IS, specifies which CIS state to target.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
1
OPTIONS:
Positive integer
RECOMMENDATION:
Set according to the desired CIS state.
OS_IS_OCC_VALENCE
When using ROKS for OS_IS, specifies which occupied orbital to excite from.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
HOMO
OPTIONS:
Positive integer
RECOMMENDATION:
Set according to the desired ROKS state. This is a 0-indexed variable (the lowest
orbital has index 0).
OS_IS_VIR_VALENCE
When using ROKS for OS_IS, specifies which virtual orbital to excite into.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
LUMO
OPTIONS:
Positive integer
RECOMMENDATION:
Set according to the desired ROKS state. This is a 0-indexed variable (the lowest
orbital has index 0).
OS_IS_SCF_ALGORITHM
When using ROKS for OS_IS, specifies the SCF algorithm for convergence of the IS.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
GDM when OS_IS_CIS_STATE = 1 or IS_OCC_VALENCE = HOMO and IS_VIR_VALENCE = LUMO
SGM otherwise
OPTIONS:
DIIS
GDM
GDM_LS
SGM
SGM_LS
RECOMMENDATION:
Use defaults.
OS_IS_DSCF_ALGORITHM
When using ROKS for OS_IS, specifies the SCF algorithm for convergence of the IS.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
NONE
OPTIONS:
MOM
IMOM
STEP
STEP_MOM
RECOMMENDATION:
When using DIIS, MOM or IMOM may be necessary to target higher valence excited states.
OS_IS_SCF_CONVERGENCE
When using ROKS or CIS_ROKS for OS_IS, specifies the SCF convergence
for the IS ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
7 for SGM- and GDM-based solvers
8 otherwise
OPTIONS:
Positive integer
RECOMMENDATION:
Modify as needed for convergence, but thresholds below 5 for descent-based methods
(GDM, SGM), and 7 for others may provide unsufficiently-converged orbitals.
OS_IS_SGM_GRADIENT
When using SGM for OS_IS_SCF_ALGORITHM, specifies the
DELTA_GRADIENT_SCALE for the IS ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
75 when using SGM as the SCF solver for the initial valence state
NONE otherwise
OPTIONS:
Positive integer below 100
RECOMMENDATION:
See DELTA_GRADIENT_SCALE $rem variable. If ROKS_IS_SS_MIXING
is set to FALSE, try the default. Otherwise, a value of around 10 might be required.
If its converging to the wrong state, try decreasing.
OS_IS_SS_MIXING
Controls whether to allow mixing between the singly-occupied orbitals during the
ROKS procedure.
INPUT SECTION: $nocis
TYPE:
BOOL
DEFAULT:
FALSE
OPTIONS:
FALSE
Supress coupling.
TRUE
Allow coupling.
RECOMMENDATION:
See ROKS_SS_MIXING $rem variable. Supressing coupling is useful when
the resuling states are difficult to converge and / or overlap significantly with the
ground state, and seems to be harmless otherwise. Certain
excitated states are particularly susceptible to this (Example 7.8.3).
Only works with descent-based solvers (GDM or SGM).
OS_FS_REFERENCE_ORB
Choice of reference orbitals for the final states (FS)
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
ROKS_2EOS for singlet valence excited states
QUARTET_ION for triplet valence excited states
OPTIONS:
OC_NOCIS
Uses ROSCF doublet core ion orbitals, rotated into the closed-shell
1C-NOCIS NTO basis
QUARTET_ION
Uses the ROSCF quartet core ion orbitals
ROKS_2EOS
Uses the orbitals optimized via ROKS.
RECOMMENDATION:
Use defaults.
OS_FS_NS_REFERENCE
Specifies a single common reference to use for all core orbitals when NUM_REF > 1.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
NONE
OPTIONS:
Non-negative integer
RECOMMENDATION:
Experimental feature. When simulating, say, the M-edge of an iron compound,
the 3s core hole reference may be useful - while it doesn’t optimize each individual
3p core hole individually, it partially captures core hole orbital realxation and provides
an unbiased reference for the set of three 3p orbitals. Note no spin-orbit coupling is
implemented at the moment for these calculations.
OS_FS_D_ION_SCF_ALGORITHM
Specifies the SCF algorithm for convergence of the doublet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
DIIS
OPTIONS:
DIIS
SGM
SGM_LS
RECOMMENDATION:
Use default. If convergence is not possible, try SGM.
OS_FS_D_ION_DSCF_ALGORITHM
Specifies the SCF algorithm for convergence of the doublet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
MOM when OS_FS_D_ION_SCF_ALGORITHM = DIIS
NONE otherwise
OPTIONS:
MOM
IMOM
STEP
STEP_MOM
RECOMMENDATION:
None.
OS_FS_D_ION_SCF_CONVERGENCE
Specifies the SCF convergence for the doublet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
0
OPTIONS:
Positive integer. i, j, k, … relate to reference 1, 2, 3, …
RECOMMENDATION:
Setting this $rem variable to 0 skips the doublet core ion calculations and
instead uses the valence excited state orbitals as a guess for either the
quartet core ion ROHF calculation or ROKS calculations.
When that fails to converge the reference orbitals, attempt to use doublet core ion
orbitals as a guess. Thresholds below 5 for SGM-Based solvers, or 7 for DIIS / MOM may
provide insufficiently converged orbitals. This may not be as critical (and perhaps
necessar) if just using them as a guess for subsequent calculations. Note
DFT orbitals may serve as better guess - specify the desired functional via
the ENV_METHOD $rem variable. When using closed-shell 1C-NOCIS
reference orbitals for the 1C-NOCIS 2eOS calculation, proper convergence
and not DFT must be used.
OS_FS_D_ION_SGM_GRADIENT
When using SGM for OS_FS_D_ION_SCF_ALGORITHM,
specifies the DELTA_GRADIENT_SCALE for the doublet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
NONE
OPTIONS:
Positive integer
RECOMMENDATION:
Anecdotically, a value of 1 - 10 seems to work well for core ions. If the ROSCF
calculation is not converging, try increasing.
OS_FS_Q_ION_SCF_ALGORITHM
Specifies the SCF algorithm for convergence of the quartet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
DIIS
OPTIONS:
DIIS
SGM
SGM_LS
RECOMMENDATION:
Use DIIS when possible. For problematic cases, use SGM.
OS_FS_Q_ION_DSCF_ALGORITHM
Specifies the SCF algorithm for convergence of the quartet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
MOM when OS_FS_D_ION_SCF_ALGORITHM = DIIS
NONE otherwise
OPTIONS:
MOM
IMOM
STEP
STEP_MOM
RECOMMENDATION:
For efficiency, attempt using MOM, IMOM, STEP, or STEP_MOM first (requires DIIS for
OS_FS_Q_ION_SCF_ALGORITHM). If the SCF procedure fails to converge or
converges to the wrong state, do not set this rem variable and attempt using SGM in
OS_FS_Q_ION_SCF_ALGORITHM.
OS_FS_Q_ION_SCF_CONVERGENCE
Specifies the SCF convergence for the quartet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
6 (for each reference) for SGM-based solvers
8 (for each reference) otherwise.
OPTIONS:
Positive integer. i, j, k, … relate to reference 1, 2, 3, …
RECOMMENDATION:
Modify as needed for convergence, but thresholds below 5 for SGM-based methods,
and 7 for others may provide unsufficiently-converged orbitals.
OS_FS_Q_ION_SGM_GRADIENT
When using SGM for OS_FS_Q_ION_SCF_ALGORITHM,
specifies the DELTA_GRADIENT_SCALE for the quartet core ion ROSCF calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
NONE
OPTIONS:
Positive integer
RECOMMENDATION:
Anecdotically, a value of 1 - 10 seems to work well for core ions. If the ROSCF
calculation is not converging, try increasing.
OS_FS_2EOS_SCF_ALGORITHM
Specifies the SCF algorithm for convergence of the
ROKS calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
SGM
OPTIONS:
DIIS
SGM
SGM_LS
RECOMMENDATION:
Use DIIS for very simple (small) molecules and low-lying valence excited states.
Else, use SGM.
OS_FS_2EOS_DSCF_ALGORITHM
Specifies the SCF algorithm for convergence of the
ROKS calculation.
INPUT SECTION: $nocis
TYPE:
STRING
DEFAULT:
MOM when OS_FS_D_ION_SCF_ALGORITHM = DIIS
NONE otherwise
OPTIONS:
MOM
IMOM
STEP
STEP_MOM
RECOMMENDATION:
Use defaults.
OS_FS_2EOS_SCF_CONVERGENCE
Specifies the SCF convergence for the
ROKS calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
6 (for each reference) for SGM-based solvers
8 (for each reference) otherwise.
OPTIONS:
Positive integer. i, j, k, … relate to reference 1, 2, 3, …
RECOMMENDATION:
Modify as needed for convergence, but thresholds below 5 for SGM-based methods,
and 7 for others may provide unsufficiently-converged orbitals.
OS_FS_2EOS_SGM_GRADIENT
When using SGM for OS_FS_2EOS_SCF_ALGORITHM,
specifies the DELTA_GRADIENT_SCALE for the core-
excited ROKS calculation.
INPUT SECTION: $nocis
TYPE:
INTEGER
DEFAULT:
75 when ROKS_FS_2EOS_SS_MIXING is set to FALSE
5 otherwise
OPTIONS:
Positive integer below 100
RECOMMENDATION:
See DELTA_GRADIENT_SCALE $rem variable. If ROKS_FS_2EOS_SS_MIXING
is set to FALSE, try the default. Otherwise, a value of around 1 - 10 might be required.
If its converging to the wrong state, try decreasing.
OS_FS_2EOS_SS_MIXING
Controls whether to allow mixing between the singly-occupied orbitals during the
ROKS procedure.
INPUT SECTION: $nocis
TYPE:
BOOL
DEFAULT:
FALSE
OPTIONS:
FALSE
Supress coupling.
TRUE
Allow coupling.
RECOMMENDATION:
See ROKS_SS_MIXING $rem variable. Supressing coupling is useful when
the resuling states are difficult to converge and / or overlap significantly with the
ground state, and seems to be harmless otherwise. 1s3s
excited states, for example, are particularly susceptible to this phenomena.
Only works with descent-based solvers (GDM or SGM).
$molecule 0 1 N 0.000000 0.000000 0.564990 N 0.000000 0.000000 -0.564990 $end $rem METHOD hf BASIS sto-3g UNRESTRICTED false GEN_SCFMAN true NOCIS true THRESH 14 MAX_SCF_CYCLES 500 INTEGRAL_SYMMETRY false POINT_GROUP_SYMMETRY false $end ! the default behavior is NOCIS $nocis ORB_OFFSET 0 NUM_REF 2 $end
$molecule 0 2 C 0.0000000 0.0000000 -0.6258140 N 0.0000000 0.0000000 0.5364120 $end $rem METHOD hf BASIS sto-3g SCF_GUESS core SCF_ALGORITHM diis_gdm MAX_SCF_CYCLES 5000 THRESH 14 SCF_CONVERGENCE 10 INTEGRAL_SYMMETRY false POINT_GROUP_SYMMETRY false $end @@@ $molecule read $end $rem METHOD hf BASIS sto-3g SCF_GUESS read UNRESTRICTED false SCF_ALGORITHM diis_gdm GEN_SCFMAN true NOCIS true MAX_SCF_CYCLES 5000 THRESH 14 SCF_CONVERGENCE 10 INTEGRAL_SYMMETRY false POINT_GROUP_SYMMETRY false $end $nocis STEX ORB_OFFSET 1 NUM_REF 1 $end
$molecule 0 3 O 0.0000000 0.0000000 0.6021380 O 0.0000000 0.0000000 -0.6021380 $end $rem METHOD hf BASIS sto-3g GEN_SCFMAN true THRESH 14 MAX_SCF_CYCLES 500 INTEGRAL_SYMMETRY false POINT_GROUP_SYMMETRY false $end @@@ $molecule read $end $rem UNRESTRICTED false SCF_GUESS read METHOD hf BASIS sto-3g GEN_SCFMAN true NOCIS true THRESH 14 MAX_SCF_CYCLES 500 INTEGRAL_SYMMETRY false POINT_GROUP_SYMMETRY false $end $nocis ONE_CENTER ORB_OFFSET 0 NUM_REF 2 $end
$comment CIS calculation on water to generate the target initial state. $end $molecule 0 1 O 0.0000 0.0000 0.1173 H 0.0000 0.7572 -0.4692 H 0.0000 -0.7572 -0.4692 $end $rem METHOD HF UNRESTRICTED FALSE BASIS DEF2-SVP SYMMETRY FALSE SYM_IGNORE TRUE GEN_SCFMAN TRUE SCF_ALGORITHM DIIS_GDM CIS_N_ROOTS 3 CIS_SINGLETS TRUE CIS_TRIPLETS FALSE REL_X2C TRUE THRESH 14 MEM_TOTAL 1000 MEM_STATIC 100 NTO_PAIRS 3 $end @@@ $comment 1C-NOCIS 2eOS singlet calculation. $end $molecule read $end $rem METHOD HF UNRESTRICTED FALSE BASIS DEF2-SVP SYMMETRY FALSE SYM_IGNORE TRUE GEN_SCFMAN TRUE SCF_GUESS READ MAX_SCF_CYCLES 0 REL_X2C TRUE NOCIS 1 THRESH 14 MEM_TOTAL 1000 MEM_STATIC 100 $end $nocis SINGLETS ONE_CENTER OS_IS CIS ! Use CIS NTOs for the valence excited state (IS) $end
$comment 1C-NOCIS 2eOS singlet calculation on pyrazine for the lowest excited state. $end $molecule 0 1 N 0.0000 0.0000 1.3814 N 0.0000 0.0000 -1.3814 C 0.0000 1.1192 0.6914 C 0.0000 -1.1192 0.6914 C 0.0000 -1.1192 -0.6914 C 0.0000 1.1192 -0.6914 H 0.0000 2.0412 1.2411 H 0.0000 -2.0412 1.2411 H 0.0000 -2.0412 -1.2411 H 0.0000 2.0412 -1.2411 $end $rem METHOD HF UNRESTRICTED FALSE BASIS STO-3G SYMMETRY FALSE SYM_IGNORE TRUE GEN_SCFMAN TRUE REL_X2C TRUE NOCIS 1 THRESH 14 MEM_TOTAL 1000 MEM_STATIC 100 $end $nocis SINGLETS ONE_CENTER LOCALIZE_ORBITALS 2 ! Localize the two nitrogen 1s orbitals NUM_REF 2 ! Two nitrogen atoms OS_IS ROKS ! Use ROKS for the valence excited state (IS) $end
$comment 1C-NOCIS 2eOS triplet calculation. Note we begin from a closed-shell reference. $end $molecule 0 1 O 0.0000 0.0000 0.60375 O 0.0000 0.0000 -0.60375 $end $rem METHOD HF UNRESTRICTED FALSE BASIS STO-3G SYMMETRY FALSE SYM_IGNORE TRUE GEN_SCFMAN TRUE SCF_ALGORITHM DIIS_GDM REL_X2C TRUE NOCIS 1 THRESH 14 MEM_TOTAL 1000 MEM_STATIC 100 $end $nocis TRIPLETS ! Activate a triplet 2eOS reference ONE_CENTER ! One-center approximation LOCALIZE_ORBITALS 2 ! Localize 2 orbitals NUM_REF 2 ! Two oxygen atoms OS_IS ROKS ! Use ROHF to converge the valence excited state (IS) OS_FS_Q_ION_SCF_CONVERGENCE 88 ! Convergence of the quartet core ion orbitals $end