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### fix setforce command

Syntax:

    fix ID group-ID setforce fx fy fz

- ID, group-ID are documented in fix command
- setforce = style name of this fix command
- fx,fy,fz = force component values

Examples:

    fix freeze indenter setforce 0.0 0.0 0.0
    fix 2 edge setforce NULL 0.0 0.0

Description:

Set each component of force on each atom in the group to the specified values fx,fy,fz. This erases all previously computed forces on the atom, though additional fixes could add new forces. This command can be used to freeze certain atoms in the simulation by zeroing their force, assuming their initial velocity zero.

Any of the fx,fy,fz values can be specified as NULL which means do not alter the force component in that dimension.

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.

This fix computes a 3-vector of forces, which can be accessed by various output commands. This is the total force on the group of atoms before the forces on individual atoms are changed by the fix. The vector values calculated by this fix are "extensive".

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 addforce, fix aveforce

Default: none