\(\renewcommand{\AA}{\text{Å}}\)

# fix planeforce command

## Syntax

    fix ID group-ID planeforce x y z

- ID, group-ID are documented in fix command

- planeforce = style name of this fix command

- x y z = 3-vector that is normal to the plane

## Examples

    fix hold boundary planeforce 1.0 0.0 0.0

## Description

Adjust the forces on each atom in the group so that only the components of force in the plane specified by the normal vector (x,y,z) remain. This is done by subtracting out the component of force perpendicular to the plane.

If the initial velocity of the atom is 0.0 (or in the plane), then it should continue to move in the plane thereafter.

## Restart, fix_modify, output, run start/stop, minimize info

No information about this fix is written to binary restart files. None of the fix_modify options are relevant to this fix. No global or per-atom quantities are stored by this fix for access by various output commands. No parameter of this fix can be used with the start/stop keywords of the run command.

The forces due to this fix are imposed during an energy minimization, invoked by the minimize command.

## Restrictions

none

## Related commands

fix lineforce

## Default

none