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compute_erotate_asphere.txt
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.. index:: compute erotate/asphere
compute erotate/asphere command
===============================
Syntax
""""""
.. parsed-literal::
compute ID group-ID erotate/asphere
* ID, group-ID are documented in :doc:`compute <compute>` command
* erotate/asphere = style name of this compute command
Examples
""""""""
.. parsed-literal::
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
:doc:`atom_style <atom_style>` and :doc:`read_data <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.
.. note::
For :doc:`2d models <dimension>`, 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 :ref:`Section_howto 15 <howto_15>` for an
overview of LAMMPS output options.
The scalar value calculated by this compute is "extensive". The
scalar value will be in energy :doc:`units <units>`.
Restrictions
""""""""""""
This compute requires that ellipsoidal particles atoms store a shape
and quaternion orientation and angular momentum as defined by the
:doc:`atom_style ellipsoid <atom_style>` command.
This compute requires that line segment particles atoms store a length
and orientation and angular velocity as defined by the :doc:`atom_style line <atom_style>` command.
This compute requires that triangular particles atoms store a size and
shape and quaternion orientation and angular momentum as defined by
the :doc:`atom_style tri <atom_style>` command.
All particles in the group must be finite-size. They cannot be point
particles.
**Related commands:** none
:doc:`compute erotate/sphere <compute_erotate_sphere>`
**Default:** none
.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html
.. _lc: Section_commands.html#comm
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