FINDIF

Performs finite difference computations of energy derivative, with respect to nuclear displacements for geometry optimizations and vibrational frequency analyses, where the required analytical derivatives are not available.

General

DISP_SIZE

Displacement size in au for finite-differences.

• Type: double

• Default: 0.005

FD_PROJECT

Do discount rotational degrees of freedom in a finite difference frequency calculation. Turned off at non-stationary geometries and in the presence of external perturbations.

• Type: boolean

• Default: true

GRADIENT_WRITE

Do write a gradient output file? If so, the filename will end in .grad, and the prefix is determined by WRITER_FILE_LABEL (if set), or else by the name of the output file plus the name of the current molecule.

• Type: boolean

• Default: false

HESSIAN_WRITE

Do write a hessian output file? If so, the filename will end in .hess, and the prefix is determined by WRITER_FILE_LABEL (if set), or else by the name of the output file plus the name of the current molecule.

• Type: boolean

• Default: false

NORMAL_MODES_WRITE

Do write a file containing the normal modes in Molden format? If so, the filename will end in .molden_normal_modes, and the prefix is determined by WRITER_FILE_LABEL (if set), or else by the name of the output file plus the name of the current molecule.

• Type: boolean

• Default: false

POINTS

Number of points for finite-differences (3 or 5)

• Type: integer

• Default: 3