2007-05-15 00:14:29 +08:00
|
|
|
<HTML>
|
|
|
|
|
<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>
|
|
|
|
|
</CENTER>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<HR>
|
|
|
|
|
|
|
|
|
|
<H3>compute coord/atom command
|
|
|
|
|
</H3>
|
|
|
|
|
<P><B>Syntax:</B>
|
|
|
|
|
</P>
|
|
|
|
|
<PRE>compute ID group-ID coord/atom cutoff
|
|
|
|
|
</PRE>
|
|
|
|
|
<UL><LI>ID, group-ID are documented in <A HREF = "compute.html">compute</A> command
|
2007-05-15 00:21:52 +08:00
|
|
|
<LI>coord/atom = style name of this compute command
|
|
|
|
|
<LI>cutoff = distance within which to count coordination neighbors (distance units)
|
2007-05-15 00:14:29 +08:00
|
|
|
</UL>
|
|
|
|
|
<P><B>Examples:</B>
|
|
|
|
|
</P>
|
|
|
|
|
<PRE>compute 1 all coord/atom 2.0
|
|
|
|
|
</PRE>
|
|
|
|
|
<P><B>Description:</B>
|
|
|
|
|
</P>
|
|
|
|
|
<P>Define a computation that calculates the coordination number for each
|
2007-09-28 07:25:52 +08:00
|
|
|
atom in a group.
|
2007-05-15 00:14:29 +08:00
|
|
|
</P>
|
2007-11-20 23:37:16 +08:00
|
|
|
<P>The value of the coordination number will be 0.0 for atoms not in the
|
|
|
|
|
specified compute group.
|
|
|
|
|
</P>
|
2007-05-15 00:14:29 +08:00
|
|
|
<P>The coordination number is defined as the number of neighbor atoms
|
2007-07-03 03:59:42 +08:00
|
|
|
within the specified cutoff distance from the central atom. Atoms not
|
|
|
|
|
in the group are included in the coordination number of atoms in the
|
|
|
|
|
group.
|
2007-05-15 00:14:29 +08:00
|
|
|
</P>
|
|
|
|
|
<P>The neighbor list needed to compute this quantity is constructed each
|
|
|
|
|
time the calculation is performed (i.e. each time a snapshot of atoms
|
|
|
|
|
is dumped). Thus it can be inefficient to compute/dump this quantity
|
|
|
|
|
too frequently or to have multiple compute/dump commands, each of a
|
|
|
|
|
<I>coord/atom</I> style.
|
|
|
|
|
</P>
|
2008-01-04 08:56:10 +08:00
|
|
|
<P><B>Output info:</B>
|
|
|
|
|
</P>
|
2009-12-05 05:04:00 +08:00
|
|
|
<P>This compute calculates a per-atom vector, which can be accessed by
|
|
|
|
|
any command that uses per-atom values from a compute as input. See
|
|
|
|
|
<A HREF = "Section_howto.html#4_15">this section</A> for an overview of LAMMPS
|
|
|
|
|
output options.
|
2008-01-04 08:56:10 +08:00
|
|
|
</P>
|
2010-01-24 07:20:05 +08:00
|
|
|
<P>The per-atom vector values will be a number >= 0.0, as explained
|
|
|
|
|
above.
|
|
|
|
|
</P>
|
2007-05-15 00:14:29 +08:00
|
|
|
<P><B>Restrictions:</B> none
|
|
|
|
|
</P>
|
2011-03-09 06:23:59 +08:00
|
|
|
<P><B>Related commands:</B>
|
|
|
|
|
</P>
|
|
|
|
|
<P><A HREF = "compute_cluster_atom.html">compute cluster/atom</A>
|
2007-05-15 00:14:29 +08:00
|
|
|
</P>
|
|
|
|
|
<P><B>Default:</B> none
|
|
|
|
|
</P>
|
|
|
|
|
</HTML>
|
