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compute_erotate_sphere.txt
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.. index:: compute erotate/sphere
compute erotate/sphere command
==============================
Syntax
""""""
.. parsed-literal::
compute ID group-ID erotate/sphere
* ID, group-ID are documented in :doc:`compute <compute>` command
* erotate/sphere = style name of this compute command
Examples
""""""""
.. parsed-literal::
compute 1 all erotate/sphere
Description
"""""""""""
Define a computation that calculates the rotational kinetic energy of
a group of spherical particles.
The rotational energy is computed as 1/2 I w^2, where I is the moment
of inertia for a sphere and w is the particle's angular velocity.
.. note::
For :doc:`2d models <dimension>`, particles are treated as
spheres, not disks, meaning their moment 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 atoms store a radius and angular velocity
(omega) as defined by the :doc:`atom_style sphere <atom_style>` command.
All particles in the group must be finite-size spheres or point
particles. They cannot be aspherical. Point particles will not
contribute to the rotational energy.
Related commands
""""""""""""""""
:doc:`compute erotate/asphere <compute_erotate_asphere>`
**Default:** none
.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html
.. _lc: Section_commands.html#comm
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