OPTKING

Performs geometry optimizations and vibrational frequency analyses.

Optimization Algorithm

CARTESIAN_SYM_TOLERANCE

Tolerance for symmetrizing cartesian geometry between steps

CONSECUTIVE_BACKSTEPS

Set number of consecutive backward steps allowed in optimization

  • Type: integer

  • Default: 0

DYNAMIC_LEVEL

Starting level for dynamic optimization (0=nondynamic, higher=>more conservative)

  • Type: integer

  • Default: 0

ENSURE_BT_CONVERGENCE

Reduce step size as necessary to ensure back-transformation of internal coordinate step to cartesian coordinates.

EXT_FORCE_BEND

Specify formula for external forces for angles between atoms

  • Type: string

  • Default: No Default

EXT_FORCE_CARTESIAN

Symmetry formula for external forces for cartesian coordinates on atoms .

  • Type: string

  • Default: No Default

EXT_FORCE_DIHEDRAL

Specify formula for external forces for dihedral angles between atoms

  • Type: string

  • Default: No Default

EXT_FORCE_DISTANCE

Specify formula for external forces for the distance between atoms

  • Type: string

  • Default: No Default

EXT_FORCE_OOFP

Specify formula for external forces for out-of-plane angles between atoms

  • Type: string

  • Default: No Default

FROZEN_BEND

Specify angles between atoms to be frozen (unchanged)

  • Type: string

  • Default: No Default

FROZEN_CARTESIAN

Specify atom and X, XY, XYZ, … 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

FROZEN_OOFP

Specify out-of-plane angles between atoms to be frozen (unchanged)

  • Type: string

  • Default: No Default

GEOM_MAXITER

Maximum number of geometry optimization steps

  • Type: integer

  • Default: 50

H_UPDATE_DEN_TOL

Denominator check for hessian update.

INTERFRAG_STEP_LIMIT

Maximum step size in bohr or radian along an interfragment coordinate

  • Type: double

  • Default: 0.5

INTRAFRAG_STEP_LIMIT

Initial maximum step size in bohr or radian along an internal coordinate

  • Type: double

  • Default: 0.5

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_POINTS

Maximum number of IRC points to collect before stopping.

  • Type: integer

  • Default: 20

IRC_STEP_SIZE

IRC step size in bohr(amu)\(^{1/2}\).

  • Type: double

  • Default: 0.2

OPT_COORDINATES

Geometry optimization coordinates to use. REDUNDANT and INTERNAL are synonyms and the default. CARTESIAN uses only cartesian coordinates. BOTH uses both redundant and cartesian coordinates.

  • Type: string

  • Possible Values: REDUNDANT, INTERNAL, CARTESIAN, BOTH

  • Default: INTERNAL

OPT_TYPE

Specifies minimum search, transition-state search, or IRC following

  • Type: string

  • Possible Values: MIN, TS, IRC

  • Default: MIN

RANGED_BEND

Specify range for angles between atoms to be constrained to (eq. value specified) analogous to the previous FIXED_BEND

  • Type: string

  • Default: No Default

RANGED_DIHEDRAL

Specify range for the dihedral angles between atoms to be constrained to (eq. value specified) analogous to the previous FIXED_DIHEDRAL

  • Type: string

  • Default: No Default

RANGED_DISTANCE

Specify range for distances between atoms to be constrained to (eq. value specified) analogous to the previous FIXED_DISTANCE

  • Type: string

  • Default: No Default

RANGED_OOFP

Specify range for the out-of-plane angles between atoms to be constrained to (eq. value specified) analogous to the old FIXED_<COORD> keyword

  • Type: string

  • Default: No Default

RFO_FOLLOW_ROOT

Do follow the initial RFO vector after the first step?

RFO_NORMALIZATION_MAX

Eigenvectors of RFO matrix whose final column is smaller than this are ignored.

  • Type: double

  • Default: 100

RFO_ROOT

Root for RFO to follow, 0 being lowest (for a minimum)

  • Type: integer

  • Default: 0

RSRFO_ALPHA_MAX

Absolute maximum value of RS-RFO.

  • Type: double

  • Default: 1e8

STEP_TYPE

Geometry optimization step type, either Newton-Raphson or Rational Function Optimization

  • Type: string

  • Possible Values: RFO, P_RFO, NR, SD, LINESEARCH

  • Default: RFO

Convergence Control

FLEXIBLE_G_CONVERGENCE

Even if a user-defined threshold is set, allow for normal, flexible convergence criteria

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, INTERFRAG_TIGHT, GAU_VERYTIGHT, TURBOMOLE, CFOUR, NWCHEM_LOOSE

  • Default: QCHEM

MAX_DISP_G_CONVERGENCE

Convergence criterion for geometry optmization: maximum displacement (internal coordinates, atomic units).

MAX_ENERGY_G_CONVERGENCE

Convergence criterion for geometry optmization: maximum energy change.

MAX_FORCE_G_CONVERGENCE

Convergence criterion for geometry optmization: maximum force (internal coordinates, atomic units).

RMS_DISP_G_CONVERGENCE

Convergence criterion for geometry optmization: rms displacement (internal coordinates, atomic units).

RMS_FORCE_G_CONVERGENCE

Convergence criterion for geometry optmization: rms force (internal coordinates, atomic units).

Hessian Update

CART_HESS_READ

Do read Cartesian Hessian? Only for experts - use FULL_HESS_EVERY instead.

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?

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: 4

INTRAFRAG_HESS

Model Hessian to guess intrafragment force constants

  • Type: string

  • Possible Values: FISCHER, SCHLEGEL, SIMPLE, LINDH, LINDH_SIMPLE

  • Default: SCHLEGEL

Fragment/Internal Coordinate Control

ADD_AUXILIARY_BONDS

Do add bond coordinates at nearby atoms for non-bonded systems?

AUXILIARY_BOND_FACTOR

This factor times standard covalent distance is used to add extra stretch coordinates.

  • Type: double

  • Default: 2.5

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

FRAG_REF_ATOMS

Specify atoms to use for reference points in interfragment coordinates

  • Type: array

  • Default: No Default

FREEZE_INTERFRAG

Do freeze all interfragment modes?

FREEZE_INTRAFRAG

Do freeze all fragments rigid?

H_BOND_CONNECT

For now, this is a general maximum distance for the definition of H-bonds

  • Type: double

  • Default: 4.3

H_GUESS_EVERY

Re-estimate the Hessian at every step, i.e., ignore the currently stored Hessian.

INTCOS_GENERATE_EXIT

Do only generate the internal coordinates and then stop?

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_COLLINEAR_TOL

Tolerance for whether to reject a set of generated reference atoms due to collinearity

INTERFRAG_COORDS

Dictionary to define a dimer. Contains “Natoms per frag”, “A Frag”, “A Ref Atoms”, “B Frag”, and “B Ref Atoms”

  • Type: string

  • Default: No Default

INTERFRAG_DIST_INV

Use 1/R for the interfragment stretching coordinate instead of R

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, PRINCIPAL_AXES

  • Default: FIXED

Misc.

OPT_RESTART

Restart the optimization from optking’s written history

  • Type: double

  • Default: 0

SAVE_OPTIMIZATION

Save OptKing’s internal classes for possible restart upon error

TEST_B

Do test B matrix?

TEST_DERIVATIVE_B

Do test derivative B matrix?

WRITE_OPT_HISTORY

Write the full history to disk. Produces a non validated OptimizationResult.

WRITE_OPT_RESULT

Write the optimization history / state to disc

WRITE_TRAJECTORY

Write Optimization Trajectory