# DIPOLE_MOMENTS

Parameters to compute oscillator strengths in the dipole approximation. [Edit on GitHub]

## Keywords

- DIPOLE_FORM

- REFERENCE

- REFERENCE_POINT

## Keyword descriptions

DIPOLE_FORM: enum = VELOCITY

  Valid values:

  - `BERRY` Based on Berry phase formula (valid for fully periodic molecular systems only)

  - `LENGTH` Length form ⟨ i | r | j ⟩ (valid for non-periodic molecular systems only)

  - `VELOCITY` Velocity form ⟨ i | d/dr | j ⟩

  Mentions: ⭐Time-Dependent DFT

  Form of dipole transition integrals. [Edit on GitHub]

REFERENCE: enum = COM

  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

  Mentions: ⭐Time-Dependent DFT

  Reference point to calculate electric dipole moments using the dipole integrals in the length form. [Edit on GitHub]

REFERENCE_POINT: real[3] = [bohr]

  Usage: REFERENCE_POINT x y z

  Mentions: ⭐Time-Dependent DFT

  User-defined reference point. [Edit on GitHub]