forked from lijiext/lammps
43 lines
1.1 KiB
HTML
43 lines
1.1 KiB
HTML
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<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>fix msd command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>fix ID group-ID msd N file
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</PRE>
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<UL><LI>ID, group-ID are documented in <A HREF = "fix.html">fix</A> command
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<LI>msd = style name of this fix command
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<LI>N = compute mean-squared displacement every this many timesteps
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<LI>file = filename to write mean-squared displacement info to
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>fix 1 all msd 100 diff.out
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Compute the mean-squared displacement of the group of atoms every N
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steps, including all effects due to atoms passing thru periodic
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boundaries. The slope of the mean-squared displacement versus time is
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proportional to the diffusion coefficient of the diffusing atoms. The
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"origin" of the displacement for each atom is its position at the time
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the fix command was issued. Write the results to the specified file.
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</P>
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<P><B>Restrictions:</B> none
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</P>
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<P><B>Related commands:</B> none
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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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