# fix nve/asphere command

## Syntax

    fix ID group-ID nve/asphere

- ID, group-ID are documented in fix command
- nve/asphere = style name of this fix command

## Examples

    fix 1 all nve/asphere

## Description

Perform constant NVE integration to update position, velocity, orientation, and angular velocity for aspherical particles in the group each timestep. V is volume; E is energy. This creates a system trajectory consistent with the microcanonical ensemble.

This fix differs from the fix nve command, which assumes point particles and only updates their position and velocity.

## 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. This fix is not invoked during `energy minimization`.

## Restrictions

This fix requires that atoms store torque and angular momementum and a quaternion as defined by the atom_style ellipsoid command.

All particles in the group must be finite-size. They cannot be point particles, but they can be aspherical or spherical as defined by their shape attribute.

## Related commands

fix nve, fix nve/sphere

Default: none