forked from lijiext/lammps
60 lines
1.6 KiB
HTML
60 lines
1.6 KiB
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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</CENTER>
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<HR>
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<H3>compute contact/atom 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 contact/atom
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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>contact/atom = 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 contact/atom
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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 number of contacts
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for each atom in a group.
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</P>
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<P>The contact number is defined for finite-size spherical particles as
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the number of neighbor atoms which overlap the central particle,
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meaning that their distance of separation is less than or equal to the
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sum of the radii of the two particles.
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</P>
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<P>The value of the contact number will be 0.0 for atoms not in the
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specified compute group.
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</P>
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<P><B>Output info:</B>
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</P>
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<P>This compute calculates a per-atom vector, whose values can be
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accessed by any command that uses per-atom values from a compute as
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input. See <A HREF = "Section_howto.html#howto_15">Section_howto 15</A> for an
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overview of LAMMPS output options.
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</P>
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<P>The per-atom vector values will be a number >= 0.0, as explained
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above.
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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 atoms store a radius as defined by the
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<A HREF = "atom_style.html">atom_style sphere</A> command.
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "compute_coord_atom.html">compute coord/atom</A>
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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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