lammps/doc/bond_class2.html

62 lines
1.5 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>bond_style class2 command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>bond_style class2
</PRE>
<P><B>Examples:</B>
</P>
<PRE>bond_style class2
bond_coeff 1 1.0 100.0 80.0 80.0
</PRE>
<P><B>Description:</B>
</P>
<P>The <I>class2</I> bond style uses the potential
</P>
<CENTER><IMG SRC = "Eqs/bond_class2.jpg">
</CENTER>
<P>where r0 is the equilibrium bond distance.
</P>
<P>See <A HREF = "#Sun">(Sun)</A> for a description of the COMPASS class2 force field.
</P>
<P>The following coefficients must be defined for each bond type via the
<A HREF = "bond_coeff.html">bond_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>R0 (distance)
<LI>K2 (energy/distance^2)
<LI>K3 (energy/distance^2)
<LI>K4 (energy/distance^2)
</UL>
<P><B>Restrictions:</B>
</P>
<P>This bond style can only be used if LAMMPS was built with the "class2"
package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section for
more info on packages.
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "bond_coeff.html">bond_coeff</A>, <A HREF = "delete_bonds.html">delete_bonds</A>
</P>
<P><B>Default:</B> none
</P>
<HR>
<A NAME = "Sun"></A>
<P><B>(Sun)</B> Sun, J Phys Chem B 102, 7338-7364 (1998).
</P>
</HTML>