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### pair_style gauss command

Syntax:

    pair_style gauss cutoff

- cutoff = global cutoff for Gauss interactions (distance units)

Examples:

    pair_style gauss 12.0
    pair_coeff * * 1.0 0.9
    pair_coeff 1 4 1.0 0.9 10.0

Description:

Style gauss computes a tethering potential of the form

between an atom and its corresponding tether site which will typically be a frozen atom in the simulation. Rc is the cutoff.

The following coefficients must be defined for each pair of atom types via the pair_coeff command as in the examples above, or in the data file or restart files read by the read_data or read_restart commands:

- A (energy units)
- B (1/distance^2 units)
- cutoff (distance units)

The last coefficient is optional. If not specified, the global cutoff is used.

Mixing, shift, table, tail correction, restart, rRESPA info:

This pair style does not support mixing. Thus, coefficients for all I,J pairs must be specified explicitly.

This pair style does not support the pair_modify shift option. There is no effect due to the Gaussian well beyond the cutoff; hence reasonable cutoffs need to be specified.

The pair_modify table and tail options are not relevant for this pair style.

This pair style does not support the pair_modify table option, since a tabulation capability does not exist for this potential.

This pair style writes its information to binary restart files, so pair_style and pair_coeff commands do not need to be specified in an input script that reads a restart file.

This pair style can only be used via the pair keyword of the run_style respa command. It does not support the inner, middle, outer keywords.

This pair style tallies an "occupancy" count of how many Gaussian-well sites have an atom within the distance at which the force is a maximum = sqrt(0.5/b). This quantity can be accessed via the compute pair command as a vector of values of length 1.

To print this quantity to the log file (with a descriptive column heading) the following commands could be included in an input script:

    compute gauss all pair gauss
    variable occ equal c_gauss[1]
    thermo_style custom step temp epair v_occ

Restrictions: none

Related commands:

pair_coeff

Default: none