INTERACTION_POTENTIAL

References: Guidon2008, Guidon2009

Defines the Coulomb, range-separated, mixed, or truncated interaction operator used for Hartree-Fock exchange. [Edit on GitHub]

Keywords

Keyword descriptions

CUTOFF_RADIUS: real = [angstrom]

Usage: CUTOFF_RADIUS 10.0

Cutoff radius for the truncated \(\frac{1}{r}\) potential or the short-range \(\frac{\mathrm{erfc}(\omega \cdot r)}{r}\) potential. For truncated Coulomb in a periodic cell, choose a radius compatible with the cell dimensions. The default value for short-range potentials when this keyword is omitted is solved from \(\frac{\mathrm{erfc}(\omega \cdot r)}{r} = \epsilon_{\mathrm{schwarz}}\) by Newton-Raphson method, with \(\epsilon_{\mathrm{schwarz}}\) set by SCREENING/EPS_SCHWARZ [Edit on GitHub]

OMEGA: real = 0.00000000E+000

Usage: OMEGA 0.5

Parameter \(\omega\) for short/longrange interaction [Edit on GitHub]

POTENTIAL_TYPE: enum = COULOMB

Usage: POTENTIAL_TYPE SHORTRANGE

Valid values:

  • COULOMB Coulomb potential: \(\frac{1}{r}\)

  • SHORTRANGE Shortrange potential: \(\frac{\mathrm{erfc}(\omega \cdot r)}{r}\)

  • LONGRANGE Longrange potential: \(\frac{\mathrm{erf}(\omega \cdot r)}{r}\)

  • MIX_CL Mix coulomb and longrange potential: \(\frac{1}{r} + \frac{\mathrm{erf}(\omega \cdot r)}{r}\)

  • GAUSSIAN Damped Gaussian potential: \(\exp{(-\omega^2 \cdot r^2)}\)

  • MIX_LG Mix Gaussian and longrange potential: \(\frac{\mathrm{erf}(\omega \cdot r)}{r} + \exp{(-\omega^2 \cdot r^2)}\)

  • 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

Selects the interaction potential used for Hartree-Fock exchange. Periodic hybrid calculations commonly use a short-range, truncated, or mixed potential. [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]