OPTKING¶
Performs geometry optimizations and vibrational frequency analyses.
Optimization Algorithm¶
CONSECUTIVE_BACKSTEPS¶
Set number of consecutive backward steps allowed in optimization
- Type: integer
- Default: 0
FIXED_BEND¶
Specify angles between atoms to be fixed (eq. value specified)
- Type: string
- Default: No Default
FIXED_DIHEDRAL¶
Specify dihedral angles between atoms to be fixed (eq. value specified)
- Type: string
- Default: No Default
FIXED_DISTANCE¶
Specify distances between atoms to be fixed (eq. value specified)
- Type: string
- Default: No Default
FROZEN_BEND¶
Specify angles between atoms to be frozen (unchanged)
- Type: string
- Default: No Default
FROZEN_DIHEDRAL¶
Specify dihedral angles between atoms to be frozen (unchanged)
- Type: string
- Default: No Default
FROZEN_DISTANCE¶
Specify distances between atoms to be frozen (unchanged)
- Type: string
- Default: No Default
GEOM_MAXITER¶
Maximum number of geometry optimization steps
- Type: integer
- Default: 50
INTERFRAG_STEP_LIMIT¶
Maximum step size in bohr or radian along an interfragment coordinate
- Type: double
- Default: 0.4
INTRAFRAG_STEP_LIMIT¶
Initial maximum step size in bohr or radian along an internal coordinate
- Type: double
- Default: 0.4
INTRAFRAG_STEP_LIMIT_MAX¶
Upper bound for dynamic trust radius [au]
- Type: double
- Default: 1.0
INTRAFRAG_STEP_LIMIT_MIN¶
Lower bound for dynamic trust radius [au]
- Type: double
- Default: 0.001
IRC_DIRECTION¶
IRC mapping direction
- Type: string
- Possible Values: FORWARD, BACKWARD
- Default: FORWARD
IRC_STEP_SIZE¶
IRC step size in bohr(amu)
.
- Type: double
- Default: 0.2
IRC_STOP¶
Decide when to stop IRC calculations
- Type: string
- Possible Values: ASK, STOP, GO
- Default: STOP
OPT_TYPE¶
Specifies minimum search, transition-state search, or IRC following
- Type: string
- Possible Values: MIN, TS, IRC
- Default: MIN
RFO_FOLLOW_ROOT¶
Do follow the initial RFO vector after the first step?
- Type: boolean
- Default: false
Convergence Control¶
FLEXIBLE_G_CONVERGENCE¶
Even if a user-defined threshold is set, allow for normal, flexible convergence criteria
- Type: boolean
- Default: false
G_CONVERGENCE¶
Set of optimization criteria. Specification of any MAX_*_G_CONVERGENCE or RMS_*_G_CONVERGENCE options will append to overwrite the criteria set here unless FLEXIBLE_G_CONVERGENCE is also on. See Table Geometry Convergence for details.
- Type: string
- Possible Values: QCHEM, MOLPRO, GAU, GAU_LOOSE, GAU_TIGHT, GAU_VERYTIGHT, TURBOMOLE, CFOUR, NWCHEM_LOOSE
- Default: QCHEM
MAX_DISP_G_CONVERGENCE¶
Convergence criterion for geometry optmization: maximum displacement (internal coordinates, atomic units).
- Type: conv double
- Default: 1.2e-3
MAX_ENERGY_G_CONVERGENCE¶
Convergence criterion for geometry optmization: maximum energy change.
- Type: conv double
- Default: 1.0e-6
MAX_FORCE_G_CONVERGENCE¶
Convergence criterion for geometry optmization: maximum force (internal coordinates, atomic units).
- Type: conv double
- Default: 3.0e-4
RMS_DISP_G_CONVERGENCE¶
Convergence criterion for geometry optmization: rms displacement (internal coordinates, atomic units).
- Type: conv double
- Default: 1.2e-3
RMS_FORCE_G_CONVERGENCE¶
Convergence criterion for geometry optmization: rms force (internal coordinates, atomic units).
- Type: conv double
- Default: 3.0e-4
Hessian Update¶
CART_HESS_READ¶
Do read Cartesian Hessian? Only for experts - use FULL_HESS_EVERY instead.
- Type: boolean
- Default: false
FULL_HESS_EVERY¶
Frequency with which to compute the full Hessian in the course of a geometry optimization. 0 means to compute the initial Hessian only, 1 means recompute every step, and N means recompute every N steps. The default (-1) is to never compute the full Hessian.
- Type: integer
- Default: -1
HESS_UPDATE¶
Hessian update scheme
- Type: string
- Possible Values: NONE, BFGS, MS, POWELL, BOFILL
- Default: BFGS
HESS_UPDATE_LIMIT¶
Do limit the magnitude of changes caused by the Hessian update?
- Type: boolean
- Default: true
HESS_UPDATE_LIMIT_MAX¶
If HESS_UPDATE_LIMIT is true, changes to the Hessian from the update are limited to the larger of HESS_UPDATE_LIMIT_SCALE * (the previous value) and HESS_UPDATE_LIMIT_MAX [au].
- Type: double
- Default: 1.00
HESS_UPDATE_LIMIT_SCALE¶
If HESS_UPDATE_LIMIT is true, changes to the Hessian from the update are limited to the larger of HESS_UPDATE_LIMIT_SCALE * (the previous value) and HESS_UPDATE_LIMIT_MAX [au].
- Type: double
- Default: 0.50
HESS_UPDATE_USE_LAST¶
Number of previous steps to use in Hessian update, 0 uses all
- Type: integer
- Default: 1
INTRAFRAG_HESS¶
Model Hessian to guess intrafragment force constants
- Type: string
- Possible Values: FISCHER, SCHLEGEL, SIMPLE, LINDH
- Default: SCHLEGEL
Fragment/Internal Coordinate Control¶
ADD_AUXILIARY_BONDS¶
Do add bond coordinates at nearby atoms for non-bonded systems?
- Type: boolean
- Default: false
COVALENT_CONNECT¶
When determining connectivity, a bond is assigned if interatomic distance is less than (this number) * sum of covalent radii.
- Type: double
- Default: 1.3
FRAG_MODE¶
For multi-fragment molecules, treat as single bonded molecule or via interfragment coordinates. A primary difference is that in MULTI mode, the interfragment coordinates are not redundant.
- Type: string
- Possible Values: SINGLE, MULTI
- Default: SINGLE
FREEZE_INTERFRAG¶
Do freeze all interfragment modes?
- Type: boolean
- Default: false
FREEZE_INTRAFRAG¶
Do freeze all fragments rigid?
- Type: boolean
- Default: false
H_BOND_CONNECT¶
For now, this is a general maximum distance for the definition of H-bonds
- Type: double
- Default: 4.3
INTCOS_GENERATE_EXIT¶
Do only generate the internal coordinates and then stop?
- Type: boolean
- Default: false
INTERFRAGMENT_CONNECT¶
When connecting disparate fragments when frag_mode = SIMPLE, a “bond” is assigned if interatomic distance is less than (this number) * sum of covalent radii. The value is then increased until all the fragments are connected (directly or indirectly).
- Type: double
- Default: 1.8
INTERFRAG_DIST_INV¶
Do use
for the stretching coordinate between fragments? Otherwise, use
.
- Type: boolean
- Default: false
INTERFRAG_HESS¶
Model Hessian to guess interfragment force constants
- Type: string
- Possible Values: DEFAULT, FISCHER_LIKE
- Default: DEFAULT
INTERFRAG_MODE¶
When interfragment coordinates are present, use as reference points either principal axes or fixed linear combinations of atoms.
- Type: string
- Possible Values: FIXED, INTERFRAGMENT
- Default: FIXED
Misc.¶
FINAL_GEOM_WRITE¶
Do save and print the geometry from the last projected step at the end of a geometry optimization? Otherwise (and by default), save and print the previous geometry at which was computed the gradient that satisfied the convergence criteria.
- Type: boolean
- Default: false
KEEP_INTCOS¶
Keep internal coordinate definition file.
- Type: boolean
- Default: false
LINESEARCH_STATIC_MAX¶
If doing a static line search, this fixes the largest step, whose largest change in an internal coordinate is set to this value (in au)
- Type: double
- Default: 0.100
LINESEARCH_STATIC_MIN¶
If doing a static line search, this fixes the shortest step, whose largest change in an internal coordinate is set to this value (in au)
- Type: double
- Default: 0.001
LINESEARCH_STATIC_N¶
If doing a static line search, scan this many points.
- Type: integer
- Default: 8
TEST_DERIVATIVE_B¶
Do test derivative B matrix?
- Type: boolean
- Default: false