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