- cutoff = global cutoff for Coulombic interactions +
- kappa = Debye length (inverse distance units)
Examples:
@@ -26,6 +30,10 @@ pair_style coul/long cutoff pair_coeff * * pair_coeff 2 2 3.5 +pair_style coul/debye 1.4 3.0 +pair_coeff * * +pair_coeff 2 2 3.5 +
pair_style coul/long 10.0 pair_coeff * *@@ -41,6 +49,14 @@ the 2 atoms, and epsilon is the dielectric constant which can be set by the dielectric command. The cutoff Rc truncates the interaction distance. +
Style coul/debye adds an additional exp() damping factor to the +Coulombic term, given by +
+
+where kappa is the Debye length. This potential is another way to +mimic the screening effect of a polar solvent. +
Style coul/long computes the same Coulombic interactions as style coul/cut except that an additional damping factor is applied so it can be used in conjunction with the kspace_style @@ -63,9 +79,9 @@ commands, or by mixing as described below:
- cutoff (distance units)
For coul/cut, the cutoff coefficient is optional. If it is not used -(as in som of the examples above), the default global value specified -in the pair_style command is used. +
For coul/cut and coul/debye, the cutoff coefficient is optional. +If it is not used (as in some of the examples above), the default +global value specified in the pair_style command is used.
For coul/long no cutoff can be specified for an individual I,J type pair via the pair_coeff command. All type pairs use the same global diff --git a/doc/pair_coul.txt b/doc/pair_coul.txt index 76eb9f4a4a..29288b46d8 100644 --- a/doc/pair_coul.txt +++ b/doc/pair_coul.txt @@ -7,14 +7,17 @@ :line pair_style coul/cut command :h3 +pair_style coul/debye command :h3 pair_style coul/long command :h3 [Syntax:] pair_style coul/cut cutoff +pair_style coul/debye kappa cutoff pair_style coul/long cutoff :pre -cutoff = global cutoff for Coulombic interactions :ul +cutoff = global cutoff for Coulombic interactions +kappa = Debye length (inverse distance units) :ul [Examples:] @@ -22,6 +25,10 @@ pair_style coul/cut 2.5 pair_coeff * * pair_coeff 2 2 3.5 :pre +pair_style coul/debye 1.4 3.0 +pair_coeff * * +pair_coeff 2 2 3.5 :pre + pair_style coul/long 10.0 pair_coeff * * :pre @@ -37,6 +44,14 @@ the 2 atoms, and epsilon is the dielectric constant which can be set by the "dielectric"_dielectric.html command. The cutoff Rc truncates the interaction distance. +Style {coul/debye} adds an additional exp() damping factor to the +Coulombic term, given by + +:c,image(Eqs/pair_debye.jpg) + +where kappa is the Debye length. This potential is another way to +mimic the screening effect of a polar solvent. + Style {coul/long} computes the same Coulombic interactions as style {coul/cut} except that an additional damping factor is applied so it can be used in conjunction with the "kspace_style"_kspace_style.html @@ -59,9 +74,9 @@ commands, or by mixing as described below: cutoff (distance units) :ul -For {coul/cut}, the cutoff coefficient is optional. If it is not used -(as in som of the examples above), the default global value specified -in the pair_style command is used. +For {coul/cut} and {coul/debye}, the cutoff coefficient is optional. +If it is not used (as in some of the examples above), the default +global value specified in the pair_style command is used. For {coul/long} no cutoff can be specified for an individual I,J type pair via the pair_coeff command. All type pairs use the same global