lammps/doc/change_box.html

64 lines
2.3 KiB
HTML

<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>change_box command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>change_box style
</PRE>
<LI>style = <I>ortho</I> or <I>triclinic</I>
<PRE> <I>ortho</I> = convert simulation box from non-orthogonal (triclinic) to orthogonal
<I>triclinic</I> = convert simulation box from orthogonal to non-orthogonal (triclinic)
</PRE>
<P><B>Examples:</B>
</P>
<PRE>change_box ortho
change_box triclinic
</PRE>
<P><B>Description:</B>
</P>
<P>By default LAMMPS runs a simulation in an orthogonal, axis-aligned
simulation box. LAMMPS can also run simulations in <A HREF = "Section_howto.html#4_12">non-orthogonal
(triclinic) simulation boxes</A>. A box is
defined as either orthogonal or non-orthogonal when it is created via
the <A HREF = "create_box.html">create_box</A>, <A HREF = "read_data.html">read_data</A>, or
<A HREF = "read_restart.html">read_restart</A> commands.
</P>
<P>This command allows you to toggle the existing simulation box from
orthogonal to non-orthogonal and vice versa. For example, an initial
equilibration simulation can be run in an orthogonal box, the box can
be toggled to non-orthogonal, and then a <A HREF = "Section_howto.html#4_13">non-equilibrium MD (NEMD)
simulation</A> can be run with deformation via
the <A HREF = "fix_deform.html">fix deform</A> command.
</P>
<P>Note that if the simulation box is currently non-orthogonal and has
non-zero tilt in xy, yz, or xz, then it cannot be converted to an
orthogonal box.
</P>
<P><B>Restrictions:</B>
</P>
<P>At the point in the input script when this command is issued, no
<A HREF = "dump.html">dumps</A> can be active, nor can a <A HREF = "fix_ave_spatial.html">fix
ave/spatial</A> or <A HREF = "fix_deform.html">fix deform</A> be
active. This is because these commands test whether the simulation
box is orthogonal when they are first issued. Note that these
commmands can appear in your script before a change_box command is
issued, so long as an <A HREF = "undump.html">undump</A> or <A HREF = "unfix.html">unfix</A>
command is also used to turn them off.
</P>
<P><B>Related commands:</B> none
</P>
<P><B>Default:</B> none
</P>
</HTML>