# DCDR

Compute analytical gradients the dipole moments. [Edit on GitHub]

Subsections

- INTERPOLATOR
- PRINT

## Keywords

- SECTION_PARAMETERS

- APT_FD

- APT_FD_DE

- APT_FD_METHOD

- DISTRIBUTED_ORIGIN

- LIST_OF_ATOMS

- ORBITAL_CENTER

- REFERENCE

- REFERENCE_POINT

- Z_MATRIX_METHOD

## Keyword descriptions

SECTION_PARAMETERS: logical = F

  Lone keyword: `T`

  Usage: &DCDR T

  controls the activation of the APT calculation [Edit on GitHub]

APT_FD: logical = F

  Lone keyword: `T`

  Usage: APT_FD T

  Use numerical differentiation to compute the APT, switches off the calculation of dcdr analytical derivatives. Requires RUN_TYPE = ENERGY_FORCE or MD. [Edit on GitHub]

APT_FD_DE: real = 3.00000000E-004

  Usage: APT_FD_DE 1.0E-4

  Electric field strength (atomic units) to use for finite differences [Edit on GitHub]

APT_FD_METHOD: enum = 2PNT

  Usage: APT_FD_METHOD FD

  Valid values:

  - `2PNT` Symmetric two-point differences.

  Numerical differentiation method [Edit on GitHub]

DISTRIBUTED_ORIGIN: logical = F

  Aliases: DO_GAUGE

  Lone keyword: `T`

  Usage: DISTRIBUTED_ORIGIN T

  Use the distributed origin (DO) gauge? [Edit on GitHub]

LIST_OF_ATOMS: integer[ ]

  Keyword can be repeated.

  Usage: LIST_OF_ATOMS {integer} {integer} .. {integer}

  Specifies a list of atoms. [Edit on GitHub]

ORBITAL_CENTER: enum = WANNIER

  Usage: ORBITAL_CENTER WANNIER

  Valid values:

  - `WANNIER` Use the Wannier centers.

  - `COMMON` Use a common center (works only for an isolate molecule).

  - `ATOM` Use the atoms as center.

  - `BOX` Boxing.

  The orbital center. [Edit on GitHub]

REFERENCE: enum = ZERO

  Valid values:

  - `COM` Use Center of Mass

  - `COAC` Use Center of Atomic Charges

  - `USER_DEFINED` Use User-defined Point

  - `ZERO` Use Origin of Coordinate System

  Gauge origin of the velocity gauge factor. [Edit on GitHub]

REFERENCE_POINT: real[3] = [bohr]

  Usage: REFERENCE_POINT x y z

  User-defined reference point of the velocity gauge factor. [Edit on GitHub]

Z_MATRIX_METHOD: logical = F

  Lone keyword: `T`

  Usage: Z_MATRIX_METHOD T

  Use Z_matrix method to solve the response equation [Edit on GitHub]