2006-09-22 00:22:34 +08:00
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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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<HR>
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<H3>dihedral_style opls command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>dihedral_style opls
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</PRE>
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<P><B>Examples:</B>
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</P>
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<PRE>dihedral_style opls
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dihedral_coeff 1 90.0 90.0 90.0 70.0
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>The <I>opls</I> dihedral style uses the potential
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</P>
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<CENTER><IMG SRC = "Eqs/dihedral_opls.jpg">
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</CENTER>
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<P>Note that the usual 1/2 factor is not included in the K values.
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</P>
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<P>This dihedral potential is used in the OPLS force field and is
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described in <A HREF = "#Watkins">(Watkins)</A>.
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</P>
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<P>The following coefficients must be defined for each dihedral type via the
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<A HREF = "dihedral_coeff.html">dihedral_coeff</A> command as in the example above, or in
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the data file or restart files read by the <A HREF = "read_data.html">read_data</A>
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or <A HREF = "read_restart.html">read_restart</A> commands:
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</P>
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<UL><LI>K1 (energy)
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<LI>K2 (energy)
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<LI>K3 (energy)
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<LI>K4 (energy)
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</UL>
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2007-06-25 22:36:36 +08:00
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<P><B>Restrictions:</B>
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</P>
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<P>This dihedral style can only be used if LAMMPS was built with the
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2011-08-27 02:53:00 +08:00
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MOLECULAR package (which it is by default). See the <A HREF = "Section_start.html#start_3">Making
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2007-06-25 22:36:36 +08:00
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LAMMPS</A> section for more info on packages.
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2006-09-22 00:22:34 +08:00
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "dihedral_coeff.html">dihedral_coeff</A>
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</P>
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<P><B>Default:</B> none
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</P>
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<HR>
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<A NAME = "Watkins"></A>
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<P><B>(Watkins)</B> Watkins and Jorgensen, J Phys Chem A, 105, 4118-4125 (2001).
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</P>
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</HTML>
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