lammps/doc/bond_morse.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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<H3>bond_style morse command
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<P><B>Syntax:</B>
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<PRE>bond_style morse
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<P><B>Examples:</B>
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<PRE>bond_style morse
bond_coeff 5 1.0 2.0 1.2
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<P><B>Description:</B>
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<P>The <I>morse</I> bond style uses the potential
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<CENTER><IMG SRC = "Eqs/bond_morse.jpg">
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<P>where r0 is the equilibrium bond distance, alpha is a stiffness
parameter, and D determines the depth of the potential well.
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<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:
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<UL><LI>D (energy)
<LI>alpha (inverse distance)
<LI>r0 (distance)
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<P><B>Restrictions:</B>
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<P>This bond style can only be used if LAMMPS was built with the
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
LAMMPS</A> section for more info on packages.
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<P><B>Related commands:</B>
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<P><A HREF = "bond_coeff.html">bond_coeff</A>, <A HREF = "delete_bonds.html">delete_bonds</A>
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<P><B>Default:</B> none
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