lammps/doc/improper_style_cvff.html

56 lines
1.4 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>improper_style cvff command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>improper_style cvff
</PRE>
<P><B>Examples:</B>
</P>
<PRE>improper_style cvff
improper_coeff 1 80.0 -1 4
</PRE>
<P><B>Description:</B>
</P>
<P>The <I>cvff</I> improper style uses the potential
</P>
<CENTER><IMG SRC = "Eqs/improper_cvff.jpg">
</CENTER>
<P>where phi is the Wilson out-of-plane angle.
</P>
<P>The following coefficients must be defined for each improper type via the
<A HREF = "improper_coeff.html">improper_coeff</A> command as in the example above, or in
the data file or restart files read by the <A HREF = "read_data.html">read_data</A>
or <A HREF = "read_restart.html">read_restart</A> commands:
</P>
<UL><LI>K (energy)
<LI>d (+1 or -1)
<LI>n (0,1,2,3,4,6)
</UL>
<P><B>Restrictions:</B>
</P>
<P>Improper styles can only be set for atom styles that allow impropers to be
defined.
</P>
<P>This improper style is part of the "molecular" package. It is only
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
LAMMPS</A> section for more info.
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "improper_coeff.html">improper_coeff</A>
</P>
<P><B>Default:</B> none
</P>
</HTML>