\(\renewcommand{\AA}{\text{Å}}\)

# compute efield/atom command

## Syntax

    compute ID group-ID efield/atom keyword val

- ID, group-ID are documented in compute command

- efield/atom = style name of this compute command

- zero or more keyword/value pairs may be appended

- keyword = pair or kspace

      pair args = yes or no
      kspace args = yes or no

## Examples

    compute 1 all efield/atom
    compute 1 all efield/atom pair yes kspace no

Used in input scripts:

    examples/PACKAGES/dielectric/in.confined
    examples/PACKAGES/dielectric/in.nopbc

## Description

Define a computation that calculates the electric field at each atom in a group. The compute should only enabled with pair and kspace styles that are provided by the DIELECTRIC package because only these styles compute the per-atom electric field at every time step.

The electric field is a 3-component vector. The value of the electric field components will be 0.0 for atoms not in the specified compute group.

The keyword/value option pairs are used in the following ways.

For the pair and kspace keywords, the real-space and reciprocal-space contributions to the electric field can be turned off and on.

## Output info

This compute calculates a per-atom vector, which can be accessed by any command that uses per-atom values from a compute as input. See the Howto output page for an overview of LAMMPS output options.

The per-atom vector values will be in electric field units.

## Restrictions

This compute is part of the DIELECTRIC package. It is only enabled if LAMMPS was built with that package.

## Related commands

dump custom

## Default

The option defaults are pair = yes and kspace = yes.