forked from lijiext/lammps
90 lines
3.1 KiB
Plaintext
90 lines
3.1 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 command :h3
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[Syntax:]
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bond_style style args :pre
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style = {none} or {hybrid} or {class2} or {fene} or {fene/expand} or \
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{harmonic} or {morse} or {nonlinear} or {quartic} :ul
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args = none for any style except {hybrid}
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{hybrid} args = list of one or more styles :pre
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[Examples:]
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bond_style harmonic
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bond_style fene
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bond_style hybrid harmonic fene :pre
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[Description:]
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Set the formula(s) LAMMPS uses to compute bond interactions between
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pairs of atoms. In LAMMPS, a bond differs from a pairwise
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interaction, which are set via the "pair_style"_pair_style.html
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command. Bonds are defined between specified pairs of atoms and
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remain in force for the duration of the simulation (unless the bond
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breaks which is possible in some bond potentials). The list of bonded
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atoms is read in by a "read_data"_read_data.html or
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"read_restart"_read_restart.html command from a data or restart file.
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By contrast, pair potentials are defined between pairs of atoms that
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are within a cutoff distance and the set of active interactions
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typically changes over time.
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Hybrid models where bonds are computed using different bond potentials
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can be setup using the {hybrid} bond style.
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The coefficients associated with a bond style can be specified in a
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data or restart file or via the "bond_coeff"_bond_coeff.html command.
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In the formulas listed for each bond style, {r} is the distance
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between the 2 atoms in the bond.
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Note that when both a bond and pair style is defined, the
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"special_bond"_special_bond.html command often needs to be used to
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turn off (or weight) the pairwise interaction that would otherwise
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exist between 2 bonded atoms.
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:line
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Here is an alphabetic list of bond styles defined in LAMMPS. Click on
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the style to display the formula it computes and coefficients
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specified by the associated "bond_coeff"_bond_coeff.html command:
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"bond_style none"_bond_style_none.html - turn off bonded interactions
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"bond_style hybrid"_bond_style_hybrid.html - define multiple styles of bond interactions :ul
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"bond_style class2"_bond_style_class2.html - COMPASS (class 2) bond
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"bond_style fene"_bond_style_fene.html - FENE (finite-extensible non-linear elastic) bond
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"bond_style fene/expand"_bond_style_fene_expand.html - FENE bonds with variable size particles
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"bond_style harmonic"_bond_style_harmonic.html - harmonic bond
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"bond_style morse"_bond_style_morse.html - Morse bond
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"bond_style nonlinear"_bond_style_nonlinear.html - nonlinear bond
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"bond_style quartic"_bond_style_quartic.html - breakable quartic bond :ul
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:line
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[Restrictions:]
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Bond styles can only be set for atom styles that allow bonds to be
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defined.
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Bond styles are part of the "molecular" package or other packages as
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noted in their documentation. They are only enabled if LAMMPS was
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built with that package. See the "Making
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LAMMPS"_Section_start.html#2_2 section for more info.
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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:]
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bond_style none
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