# INTERACTION_POTENTIAL

Parameters the interaction potential in computing the biel integrals [Edit on GitHub]

## Keywords

- OMEGA

- POTENTIAL_DATA

- POTENTIAL_TYPE

- SCALE_COULOMB

- SCALE_LONGRANGE

- TRUNCATION_RADIUS

## Keyword descriptions

OMEGA: real = 5.00000000E-001

  Usage: OMEGA 0.5

  Range separation parameter for the longrange or shortrange potential. Only valid when longrange or shortrange potential is requested. [Edit on GitHub]

POTENTIAL_DATA: string = t_sh_p_s_c.dat

  Aliases: TSHPSC_DATA ,T_C_G_DATA

  Usage: TShPSC_DATA t_sh_p_s_c.dat

  Location of the file TShPSC.dat or t_c_g.dat that contains the data for the evaluation of the evaluation of the truncated potentials [Edit on GitHub]

POTENTIAL_TYPE: enum = COULOMB

  Usage: POTENTIAL_TYPE TSHPSC

  Valid values:

  - `COULOMB` Coulomb potential: 1/r

  - `TSHPSC`

    Range | TShPSC
    --- | ---
    \( x \leq R_c \) | \( 1/x - s/R_c \)
    \( R_c < x \leq nR_c \) | \( (1 - s)/R_c - (x - R_c)/R_c^2 + (x - R_c)^2/R_c^3 - (2n^2 - 7n + 9 - 4s)(x - R_c)^3/(R_c^4(n^2 - 2n + 1)(n - 1)) + (6-3s - 4n + n^2)(x - R_c)^4/(R_c^5(n^4 - 4n^3 + 6n^2 - 4n + 1)) \) (4th order polynomial)
    \( x > nR_c \) | \( 0 \)

  - `LONGRANGE` Longrange Coulomb potential: \( \operatorname{erf}(wr)/r \)

  - `SHORTRANGE` Shortrange Coulomb potential: \( \operatorname{erfc}(wr)/r \)

  - `TRUNCATED` Truncated Coulomb potential

  - `MIX_CL` Mixed Coulomb/Longrange Coulomb potential

  - `IDENTITY` Delta potential

  Which interaction potential should be used (Coulomb, TShPSC operator). [Edit on GitHub]

SCALE_COULOMB: real = 1.00000000E+000

  Usage: SCALE_COULOMB 0.5

  Scaling factor of (truncated) Coulomb potential in mixed (truncated) Coulomb/Longrange potential. Only valid when mixed potential is requested. [Edit on GitHub]

SCALE_LONGRANGE: real = 1.00000000E+000

  Usage: SCALE_LONGRANGE 0.5

  Scaling factor of longrange Coulomb potential in mixed (truncated) Coulomb/Longrange potential. Only valid when mixed potential is requested. [Edit on GitHub]

TRUNCATION_RADIUS: real = 5.29177209E+000 [angstrom]

  Aliases: CUTOFF_RADIUS

  Usage: TRUNCATION_RADIUS 10.0

  Determines truncation radius for the truncated potentials. Only valid when doing truncated calculations [Edit on GitHub]