# ADD_MM_CHARGE

Section can be repeated.

Specify information to add a classical charge before the QM/MM energies and forces evaluation [Edit on GitHub]

## Keywords

- ALPHA

- ATOM_INDEX_1

- ATOM_INDEX_2

- CHARGE

- CORR_RADIUS

- RADIUS

## Keyword descriptions

ALPHA: real

  Usage: ALPHA real

  Specifies the scaling factor that defines the movement along the defined direction [Edit on GitHub]

ATOM_INDEX_1: integer

  Aliases: MM1

  Usage: ATOM_INDEX_1 integer

  Specifies the index of the first atom defining the direction along which the atom will be added [Edit on GitHub]

ATOM_INDEX_2: integer

  Aliases: MM2

  Usage: ATOM_INDEX_2 integer

  Specifies the index of the second atom defining the direction along which the atom will be added [Edit on GitHub]

CHARGE: real = 0.00000000E+000

  Usage: CHARGE real

  Specifies the charge for the added source of QM/MM potential [Edit on GitHub]

CORR_RADIUS: real = 8.00000000E-001 [angstrom]

  Usage: CORR_RADIUS real

  Specifies the correction radius used for the QM/MM electrostatic coupling for the added source [Edit on GitHub]

RADIUS: real = 8.00000000E-001 [angstrom]

  Usage: RADIUS real

  Specifies the radius used for the QM/MM electrostatic coupling for the added source [Edit on GitHub]