forked from lijiext/lammps
90 lines
2.4 KiB
Plaintext
90 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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pair_style morse command :h3
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pair_style morse/opt command :h3
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[Syntax:]
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pair_style morse cutoff :pre
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cutoff = global cutoff for Morse interactions (distance units) :ul
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[Examples:]
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pair_style morse 2.5
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pair_style morse/opt 2.5
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pair_coeff * * 100.0 2.0 1.5
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pair_coeff 1 1 100.0 2.0 1.5 3.0 :pre
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[Description:]
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Style {morse} computes pairwise interactions with the formula
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:c,image(Eqs/pair_morse.jpg)
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Rc is the cutoff.
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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:
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D0 (energy units)
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alpha (1/distance units)
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r0 (distance units)
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cutoff (distance units) :ul
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The last coefficient is optional. If not specified, the global morse
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cutoff is used.
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Style {morse/opt} is an optimized version of style {morse} that should
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give identical answers. Depending on system size and the processor
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you are running on, it may be 5-25% faster (for the pairwise portion
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of the run time).
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:line
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[Mixing, shift, table, tail correction, restart, rRESPA info]:
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None of these pair styles support mixing. Thus, coefficients for all
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I,J pairs must be specified explicitly.
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All of these pair styles support the "pair_modify"_pair_modify.html
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shift option for the energy of the pair interaction.
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The "pair_modify"_pair_modify.html table options is not relevant for
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the Morse pair styles.
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None of these pair styles support the "pair_modify"_pair_modify.html
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tail option for adding long-range tail corrections to energy and
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pressure.
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All of these pair styles write their 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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These pair styles can only be used via the {pair} keyword of the
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"run_style respa"_run_style.html command. They do not support the
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{inner}, {middle}, {outer} keywords.
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:line
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[Restrictions:]
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The {morse/opt} style is part of the "opt" package. It is only
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enabled if LAMMPS was built with that package. See the "Making
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LAMMPS"_Section_start.html#2_3 section for more info.
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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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