forked from lijiext/lammps
69 lines
2.3 KiB
HTML
69 lines
2.3 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 volume/rescale 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 volume/rescale N keyword args ...
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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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</UL>
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<LI>volume/rescale = style name of this fix command
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<LI>N = perform volume rescaling every this many timesteps
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<LI>one or more keyword/value pairs may be appended to the args
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<LI>keyword = <I>x</I> or <I>y</I> or <I>z</I>
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<PRE> <I>x</I>, <I>y</I>, <I>z</I> args = lo,hi = desired simulation box boundaries
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at end of run (distance units)
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</PRE>
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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 volume/rescale 100 x -9.0 9.0 z -5.0 5.0
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Enable a volume (density) change during a simulation. Each of the 3
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box dimensions is controlled separately. Any dimension being varied
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by this command must be periodic - see the <A HREF = "boundary.html">boundary</A>
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command. Dimensions not varied by this command can be periodic or
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non-periodic. The volume associated with an unspecified dimension can
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also be controlled by a <A HREF = "fix_npt.html">fix npt</A> command.
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</P>
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<P>The initial simulation box boundaries at the beginning of a run are
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specified by the <A HREF = "create_box.html">create_box</A> or
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<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A> command
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used to setup the simulation, or they are the values at the end of the
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previous run. The desired simulation box boundaries at the end of the
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run are given by the <I>lo</I> and <I>hi</I> arguments. See the
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<A HREF = "units.html">units</A> command for a discussion of distance units.
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</P>
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<P>Every Nth timestep during the run, the simulation box is expanded or
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contracted to a ramped value between the initial and final values.
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The <A HREF = "run.html">run</A> command documents how to make the ramping take
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place across multiple runs. The coordinates of all atoms in the group
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are also scaled to the new box size.
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</P>
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<P><B>Restrictions:</B>
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</P>
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<P>Any dimension being varied by this fix must be periodic.
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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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