2008-03-18 08:24:08 +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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2008-03-19 05:02:30 +08:00
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<H3>compute erotate/sphere command
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2008-03-18 08:24:08 +08:00
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</H3>
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<P><B>Syntax:</B>
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</P>
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2008-03-19 05:02:30 +08:00
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<PRE>compute ID group-ID erotate/sphere
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2008-03-18 08:24:08 +08:00
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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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2008-03-19 05:02:30 +08:00
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<LI>erotate/sphere = style name of this compute command
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2008-03-18 08:24:08 +08:00
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</UL>
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<P><B>Examples:</B>
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</P>
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2008-03-19 05:02:30 +08:00
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<PRE>compute 1 all erotate/sphere
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2008-03-18 08:24:08 +08:00
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</PRE>
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<P><B>Description:</B>
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</P>
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2008-03-19 05:02:30 +08:00
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<P>Define a computation that calculates the rotational kinetic energy of
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a group of spherical particles.
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2008-03-18 08:24:08 +08:00
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</P>
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2008-03-19 05:02:30 +08:00
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<P>The rotational energy is computed as 1/2 I w^2, where I is the moment
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of inertia for a sphere and w is the particle's angular velocity.
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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 spheres, not disks, meaning their moment of inertia will be the
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same as in 3d.
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2008-03-18 08:24:08 +08:00
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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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2010-03-03 05:51:16 +08:00
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<P>The scalar value calculated by this compute is "extensive". The
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scalar value will be in energy <A HREF = "units.html">units</A>.
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2010-01-24 07:20:05 +08:00
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</P>
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2008-03-19 05:02:30 +08:00
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<P><B>Restrictions:</B>
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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 velocity (omega) as
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defined by the <A HREF = "atom_style.html">atom_style</A>. It also require they
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store either a per-particle diameter or per-type <A HREF = "shape.html">shape</A>.
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2008-03-18 08:24:08 +08:00
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</P>
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2009-06-27 02:22:33 +08:00
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<P>All particles in the group must be finite-size spheres or point
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particles. They cannot be aspherical. Point particles will not
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contribute to the rotational energy.
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</P>
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<P><B>Related commands:</B>
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</P>
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2010-05-07 23:11:21 +08:00
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<P><A HREF = "compute_erotate_asphere.html">compute erotate/asphere</A>
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2008-03-18 08:24:08 +08:00
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</P>
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<P><B>Default:</B> none
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</P>
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</HTML>
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