lammps/doc/compute_erotate_asphere.html

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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
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<H3>compute erotate/asphere command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>compute ID group-ID erotate/asphere
</PRE>
<UL><LI>ID, group-ID are documented in <A HREF = "compute.html">compute</A> command
<LI>erotate/asphere = style name of this compute command
</UL>
<P><B>Examples:</B>
</P>
<PRE>compute 1 all erotate/asphere
</PRE>
<P><B>Description:</B>
</P>
<P>Define a computation that calculates the rotational kinetic energy of
a group of aspherical particles.
</P>
<P>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.
</P>
<P>IMPORTANT NOTE: For <A HREF = "dimension.html">2d models</A>, particles are treated
as ellipsoids, not ellipses, meaning their moments of inertia will be
the same as in 3d.
</P>
<P><B>Output info:</B>
</P>
<P>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 <A HREF = "Section_howto.html#4_15">this section</A> for an overview of
LAMMPS output options.
</P>
<P>The scalar value calculated by this compute is "extensive". The
scalar value will be in energy <A HREF = "units.html">units</A>.
</P>
<P><B>Restrictions:</B>
</P>
<P>This compute requires that atoms store a shape and quaternion
orientation and angular momentum as defined by the <A HREF = "atom_style.html">atom_style
ellipsoid</A> command.
</P>
<P>All particles in the group must be finite-size. They cannot be point
particles.
</P>
<P><B>Related commands:</B> none
</P>
<P><A HREF = "compute_erotate_sphere.html">compute erotate/sphere</A>
</P>
<P><B>Default:</B> none
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