forked from lijiext/lammps
54 lines
1.3 KiB
HTML
54 lines
1.3 KiB
HTML
<HTML>
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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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</CENTER>
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<HR>
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<H3>dihedral_style quadratic 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 quadratic
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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 quadratic
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dihedral_coeff 100.0 80.0
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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>quadratic</I> dihedral style uses the potential:
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</P>
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<CENTER><IMG SRC = "Eqs/dihedral_quadratic.jpg">
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</CENTER>
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<P>This dihedral potential can be used to keep a dihedral in a predefined value.
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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>K (energy)
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<LI>phi0 (degrees)
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</UL>
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<HR>
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<P><B>Restrictions:</B>
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</P>
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<P>This angle style can only be used if LAMMPS was built with the
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USER_MISC package. See the <A HREF = "Section_start.html#start_3">Making LAMMPS</A>
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section for more info on packages.
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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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</HTML>
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