2008-03-20 01:04:31 +08:00
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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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<HR>
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<H3>compute erotate/asphere command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>compute ID group-ID erotate/asphere
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</PRE>
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<UL><LI>ID, group-ID are documented in <A HREF = "compute.html">compute</A> command
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<LI>erotate/asphere = style name of this compute command
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>compute 1 all erotate/asphere
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Define a computation that calculates the rotational kinetic energy of
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a group of aspherical particles.
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</P>
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<P>The rotational kinetic energy is computed as 1/2 I w^2, where I is the
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inertia tensor for the aspherical particle and w is its angular
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velocity, which is computed from its angular momentum.
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</P>
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<P>IMPORTANT NOTE: For <A HREF = "dimension.html">2d models</A>, particles are treated
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as ellipsoids, not ellipses, meaning their moments of inertia will be
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the same as in 3d.
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</P>
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<P><B>Output info:</B>
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</P>
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2009-12-04 07:58:11 +08:00
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<P>This compute calculates a global scalar (the KE). This value can be
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used by any command that uses a global scalar value from a compute as
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input. See <A HREF = "Section_howto.html#4_15">this section</A> for an overview of
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LAMMPS output options.
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</P>
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2008-03-20 01:04:31 +08:00
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<P>The scalar value calculated by this compute is "extensive", meaning it
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it scales with the number of atoms in the simulation.
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</P>
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<P><B>Restrictions:</B>
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</P>
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<P>This compute requires that particles be represented as extended
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ellipsoids and not point particles. This means they will have an
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angular momentum and a shape which is determined by the
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<A HREF = "shape.html">shape</A> command.
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</P>
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2009-06-27 02:22:33 +08:00
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<P>This compute requires that atoms store angular momentum and a
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quaternion to represent their orientation, as defined by the
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<A HREF = "atom_style.html">atom_style</A>. It also require they store a per-type
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<A HREF = "shape.html">shape</A>. The particles cannot store a per-particle
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diameter or per-particle mass.
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</P>
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<P>All particles in the group must be finite-size. They cannot be point
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particles, but they can be aspherical or spherical.
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</P>
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2008-03-20 01:04:31 +08:00
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<P><B>Related commands:</B> none
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</P>
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2009-06-27 02:22:33 +08:00
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<P><A HREF = "compute_rotate_sphere.html">compute erotate/sphere</A>
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</P>
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2008-03-20 01:04:31 +08:00
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<P><B>Default:</B> none
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</P>
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</HTML>
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