<UL><LI>style = <I>none</I> or <I>hybrid</I> or <I>charmm</I> or <I>class2</I> or <I>harmonic</I> or <I>helix</I> or <I>multi/harmonic</I> or <I>opls</I>
</UL>
<P><B>Examples:</B>
</P>
<PRE>dihedral_style harmonic
dihedral_style multi/harmonic
dihedral_style hybrid harmonic charmm
</PRE>
<P><B>Description:</B>
</P>
<P>Set the formula(s) LAMMPS uses to compute dihedral interactions
between quadruplets of atoms, which remain in force for the duration
of the simulation. The list of dihedral quadruplets is read in by a
<AHREF ="read_data.html">read_data</A> or <AHREF ="read_restart.html">read_restart</A> command
from a data or restart file.
</P>
<P>Hybrid models where dihedrals are computed using different dihedral
potentials can be setup using the <I>hybrid</I> dihedral style.
</P>
<P>The coefficients associated with a dihedral style can be specified in a
data or restart file or via the <AHREF ="dihedral_coeff.html">dihedral_coeff</A> command.
</P>
<P>In the formulas listed for each dihedral style, <I>phi</I> is the torsional