pair_style zero command — LAMMPS documentation

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# pair_style zero command

## Syntax

    pair_style zero cutoff [nocoeff] [full]

- zero = style name of this pair style

- cutoff = global cutoff (distance units)

- nocoeff = ignore all pair_coeff parameters (optional)

- full = build full neighbor list (optional)

## Examples

    pair_style zero 10.0
    pair_style zero 5.0 nocoeff
    pair_coeff * *
    pair_coeff 1 2*4 3.0

## Description

Define a global or per-type cutoff length for the purpose of building a neighbor list and acquiring ghost atoms, but do not compute any pairwise forces or energies.

This can be useful for fixes or computes which require a neighbor list to enumerate pairs of atoms within some cutoff distance, but when pairwise forces are not otherwise needed. Examples are the fix bond/create, compute rdf, compute voronoi/atom commands.

Note that the comm_modify cutoff command can be used to ensure communication of ghost atoms even when a pair style is not defined, but it will not trigger neighbor list generation.

The optional nocoeff flag allows to read data files with a PairCoeff section for any pair style. Similarly, any pair_coeff commands will only be checked for the atom type numbers and the rest ignored. In this case, only the global cutoff will be used.

Added in version 3Nov2022.

The optional full flag builds a full neighbor list instead of the default half neighbor list.

The following coefficients must be defined for each pair of atoms 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, or by mixing as described below:

- cutoff (distance units)

This coefficient is optional. If not specified, the global cutoff specified in the pair_style command is used. If the pair_style has been specified with the optional nocoeff flag, then a cutoff pair coefficient is ignored.

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

The cutoff distance for this pair style can be mixed. The default mix value is geometric. See the “pair_modify” command for details.

This pair style does not support the pair_modify shift, table, and tail options.

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 supports the use of the inner, middle, and outer keywords of the run_style respa command.

## Restrictions

none

## Related commands

pair_style none

## Default

none