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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Page</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Chapter_commands.html#comm">LAMMPS Commands</A>
</CENTER>
<HR>
<H3>min_style command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>min_style style
</PRE>
<UL><LI>style = <I>cg</I> or <I>cg/fr</I> or <I>sd</I>
</UL>
<P><B>Examples:</B>
</P>
<PRE>min_style cg
min_style sd
</PRE>
<P><B>Description:</B>
</P>
<P>Choose a minimization algorithm to use when a <A HREF = "minimize.html">minimize</A>
command is performed.
</P>
<P>Style <I>cg</I> is the Polak-Ribiere (PR) version of the conjugate gradient
(CG) algorithm. At each iteration the force gradient is combined with
the previous iteration information to compute a new search direction
perpendicular (conjugate) to previous search directions. The PR
variant affects how the direction is chosen and how the CG method is
restarted when it ceases to make progress. The PR variant is thought
to be the most effective CG choice.
</P>
<P>Style <I>cg/fr</I> is the Fletcher-Reeves version of the conjugate gradient
algorithm.
</P>
<P>Style <I>sd</I> is a steepest descent algorithm. At each iteration, the
downhill direction corresponding to the force vector (negative
gradient of energy) is searched along by a 1d line search. Typically,
steepest descent will not converge as quickly as CG, but may be more
robust in some situations.
</P>
<P><B>Restrictions:</B> none
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "min_modify.html">min_modify</A>, <A HREF = "minimize.html">minimize</A>
</P>
<P><B>Default:</B>
</P>
<PRE>min_style cg
</PRE>
</HTML>
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