# RESP

References: Golze2015

Requests a RESP fit of charges. When using a periodic Poisson solver and a periodic cell, the periodic RESP routines are used. If the Hartree potential matches with the one of an isolated system (i.e. isolated Poisson solver and big, nonperiodic cells), the nonperiodic RESP routines are automatically used. All restraints are harmonic! [Edit on GitHub]

Subsections

- CONSTRAINT
- PRINT
- RESTRAINT
- SLAB_SAMPLING
- SPHERE_SAMPLING

## Keywords

- INTEGER_TOTAL_CHARGE

- RESTRAIN_HEAVIES_STRENGTH

- RESTRAIN_HEAVIES_TO_ZERO

- STRIDE

- USE_REPEAT_METHOD

- WIDTH

## Keyword descriptions

INTEGER_TOTAL_CHARGE: logical = T

  Usage: INTEGER_TOTAL_CHARGE TRUE

  Mentions: ⭐RESP Charges

  Forces the total charge to be integer [Edit on GitHub]

RESTRAIN_HEAVIES_STRENGTH: real = 1.00000000E-006

  Usage: RESTRAIN_HEAVIES_STRENGTH 0.0001

  Mentions: ⭐RESP Charges

  If defined, enforce the restraint of non-hydrogen atoms to zero. Its value is the strength of the restraint on the heavy atoms. [Edit on GitHub]

RESTRAIN_HEAVIES_TO_ZERO: logical = T

  Lone keyword: `T`

  Usage: RESTRAIN_HEAVIES_TO_ZERO FALSE

  Mentions: ⭐RESP Charges

  Restrain non-hydrogen atoms to zero. [Edit on GitHub]

STRIDE: integer[ ] = 2 2 2

  Usage: STRIDE 2 2 2

  The stride (X,Y,Z) used to write the cube file (larger values result in smaller cube files). You can provide 3 numbers (for X,Y,Z) or 1 number valid for all components. [Edit on GitHub]

USE_REPEAT_METHOD: logical = F

  Lone keyword: `T`

  Usage: USE_REPEAT_METHOD

  References: Campana2009

  Mentions: ⭐RESP Charges

  Fits the variance of the potential, i.e. the deviation from the mean value of the potential within the selected range. The evaluation of the potentials is still treated within the GPW approach as described in [Golze2015]. When used in conjunction with INTEGER_TOTAL_CHARGE = T and SPHERE_SAMPLING, the results will be very similar to the REPEAT charges given in [Campana2009]. In most cases switching on this option gives reasonable atomic charges without the need to define any restraints. Note that by switching on this option, RESTRAIN_HEAVIES_TO_ZERO will be switched off. [Edit on GitHub]

WIDTH: real = 1.12490000E+001 [angstrom^-2]

  Usage: WIDTH <real>

  Specifies the value of the width of the Gaussian charge distribution carried by each atom. Needs only to be specified when using a periodic Poisson solver. [Edit on GitHub]