# INTERACTION_POTENTIAL

References: Guidon2008, Guidon2009

Sets up interaction potential if requested [Edit on GitHub]

## Keywords

- CUTOFF_RADIUS

- OMEGA

- POTENTIAL_TYPE

- SCALE_COULOMB

- SCALE_GAUSSIAN

- SCALE_LONGRANGE

- T_C_G_DATA

## Keyword descriptions

CUTOFF_RADIUS: real = [angstrom]

  Usage: CUTOFF_RADIUS 10.0

  Determines cutoff radius (in Angstroms) for the truncated 1/r potential. Only valid when doing truncated calculation [Edit on GitHub]

OMEGA: real = 0.00000000E+000

  Usage: OMEGA 0.5

  Parameter for short/longrange interaction [Edit on GitHub]

POTENTIAL_TYPE: enum = COULOMB

  Usage: POTENTIAL_TYPE SHORTRANGE

  Valid values:

  - `COULOMB` Coulomb potential: 1/r

  - `SHORTRANGE` Shortrange potential: erfc(omega*r)/r

  - `LONGRANGE` Longrange potential: erf(omega*r)/r

  - `MIX_CL` Mix coulomb and longrange potential: 1/r + erf(omega*r)/r

  - `GAUSSIAN` Damped Gaussian potential: exp(-omega^2*r^2)

  - `MIX_LG` Mix Gaussian and longrange potential: erf(omegar)/r + exp(-omega^2r^2)

  - `IDENTITY` Overlap

  - `TRUNCATED` Truncated coulomb potential: if (r < R_c) 1/r else 0

  - `MIX_CL_TRUNC` Truncated Mix coulomb and longrange potential, assumes/requires that the erf has fully decayed at R_c

  Which interaction potential should be used (Coulomb, longrange or shortrange). [Edit on GitHub]

SCALE_COULOMB: real = 1.00000000E+000

  Usage: SCALE_COULOMB 1.0

  Scales Hartree-Fock contribution arising from a coulomb potential. Only valid when doing a mixed potential calculation [Edit on GitHub]

SCALE_GAUSSIAN: real = 1.00000000E+000

  Usage: SCALE_GAUSSIAN 1.0

  Scales Hartree-Fock contribution arising from a gaussian potential. Only valid when doing a mixed potential calculation [Edit on GitHub]

SCALE_LONGRANGE: real = 1.00000000E+000

  Usage: SCALE_LONGRANGE 1.0

  Scales Hartree-Fock contribution arising from a longrange potential. Only valid when doing a mixed potential calculation [Edit on GitHub]

T_C_G_DATA: string = t_c_g.dat

  Usage: T_C_G_DATA /data/t_c_g.dat

  Location of the file t_c_g.dat that contains the data for the evaluation of the truncated gamma function [Edit on GitHub]