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lammps/doc/bond_hybrid.txt
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
:line
bond_style hybrid command :h3
[Syntax:]
bond_style hybrid style1 style2 ... :pre
style1,style2 = list of one or more bond styles :ul
[Examples:]
bond_style hybrid harmonic fene
bond_coeff 1 harmonic 80.0 1.2
bond_coeff 2* fene 30.0 1.5 1.0 1.0 :pre
[Description:]
The {hybrid} style enables the use of multiple bond styles in one
simulation. A bond style is assigned to each bond type. For example,
bonds in a polymer flow (of bond type 1) could be computed with a
{fene} potential and bonds in the wall boundary (of bond type 2) could
be computed with a {harmonic} potential. The assignment of bond type
to style is made via the "bond_coeff"_bond_coeff.html command or in
the data file.
In the bond_coeff commands, the name of a bond style must be added
after the bond type, with the remaining coefficients being those
appropriate to that style. In the example above, the 2 bond_coeff
commands set bonds of bond type 1 to be computed with a {harmonic}
potential with coefficients 80.0, 1.2 for K, r0. All other bond types
(2-N) are computed with a {fene} potential with coefficients 30.0,
1.5, 1.0, 1.0 for K, R0, epsilon, sigma.
If bond coefficients are specified in the data file read via the
"read_data"_read_data.html command, then the same rule applies.
E.g. "harmonic" or "fene" must be added after the bond type, for each
line in the "Bond Coeffs" section, e.g.
Bond Coeffs :pre
1 harmonic 80.0 1.2
2 fene 30.0 1.5 1.0 1.0
... :pre
A bond style of {none} with no additional coefficients can be used in
place of a bond style, either in a input script bond_coeff command or
in the data file, if you desire to turn off interactions for specific
bond types.
:line
[Restrictions:]
This bond style can only be used if LAMMPS was built with the
MOLECULAR package (which it is by default). See the "Making
LAMMPS"_Section_start.html#start_3 section for more info on packages.
Unlike other bond styles, the hybrid bond style does not store bond
coefficient info for individual sub-styles in a "binary restart
files"_restart.html. Thus when retarting a simulation from a restart
file, you need to re-specify bond_coeff commands.
[Related commands:]
"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html
[Default:] none
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