forked from lijiext/lammps
87 lines
2.5 KiB
Plaintext
87 lines
2.5 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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pair_style lj/expand command :h3
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[Syntax:]
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pair_style lj/expand cutoff :pre
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cutoff = global cutoff for lj/expand interactions (distance units) :ul
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[Examples:]
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pair_style lj/expand 2.5
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pair_coeff * * 1.0 1.0 0.5
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pair_coeff 1 1 1.0 1.0 -0.2 2.0 :pre
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[Description:]
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Style {lj/expand} computes a LJ interaction with a distance shifted by
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delta which can be useful when particles are of different sizes, since
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it is different that using different sigma values in a standard LJ
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formula:
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:c,image(Eqs/pair_lj_expand.jpg)
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Rc is the cutoff which does not include the delta distance. I.e. the
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actual force cutoff is the sum of cutoff + delta.
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The following coefficients must be defined for each pair of atoms
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types via the "pair_coeff"_pair_coeff.html command as in the examples
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above, or in the data file or restart files read by the
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"read_data"_read_data.html or "read_restart"_read_restart.html
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commands, or by mixing as described below:
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epsilon (energy units)
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sigma (distance units)
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delta (distance units)
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cutoff (distance units) :ul
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The delta values can be positive or negative. The last coefficient is
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optional. If not specified, the global LJ cutoff is used.
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:line
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[Mixing, shift, table, tail correction, restart, rRESPA info]:
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For atom type pairs I,J and I != J, the epsilon, sigma, and shift
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coefficients and cutoff distance for this pair style can be mixed.
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Shift is always mixed via an {arithmetic} rule. The other
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coefficients are mixed according to the pair_modify mix value. The
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default mix value is {geometric}. See the "pair_modify" command for
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details.
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This pair style supports the "pair_modify"_pair_modify.html shift
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option for the energy of the pair interaction.
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The "pair_modify"_pair_modify.html table option is not relevant
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for this pair style.
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This pair style supports the "pair_modify"_pair_modify.html tail
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option for adding a long-range tail correction to the energy and
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pressure of the pair interaction.
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This pair style writes its information to "binary restart
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files"_restart.html, so pair_style and pair_coeff commands do not need
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to be specified in an input script that reads a restart file.
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This pair style can only be used via the {pair} keyword of the
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"run_style respa"_run_style.html command. It does not support the
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{inner}, {middle}, {outer} keywords.
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:line
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[Restrictions:] none
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[Related commands:]
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"pair_coeff"_pair_coeff.html
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[Default:] none
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