Syntax:
compute ID group-ID erotate/asphere
Examples:
compute 1 all erotate/asphere
Description:
Define a computation that calculates the rotational kinetic energy of a group of aspherical particles. The aspherical particles can be ellipsoids, or line segments, or triangles. See the atom_style and read_data commands for descriptions of these options.
For all 3 types of particles, the rotational kinetic energy is computed as 1/2 I w^2, where I is the inertia tensor for the aspherical particle and w is its angular velocity, which is computed from its angular momentum if needed.
IMPORTANT NOTE: For 2d models, ellipsoidal particles are treated as ellipsoids, not ellipses, meaning their moments of inertia will be the same as in 3d.
Output info:
This compute calculates a global scalar (the KE). This value can be used by any command that uses a global scalar value from a compute as input. See Section_howto 15 for an overview of LIGGGHTS(R)-PUBLIC output options.
The scalar value calculated by this compute is "extensive". The scalar value will be in energy units.
Restrictions:
This compute requires that ellipsoidal particles atoms store a shape and quaternion orientation and angular momentum as defined by the atom_style ellipsoid command.
This compute requires that line segment particles atoms store a length and orientation and angular velocity as defined by the atom_style line command.
This compute requires that triangular particles atoms store a size and shape and quaternion orientation and angular momentum as defined by the atom_style tri command.
All particles in the group must be finite-size. They cannot be point particles.
Related commands: none
Default: none