forked from lijiext/lammps
61 lines
1.6 KiB
Plaintext
61 lines
1.6 KiB
Plaintext
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"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 soft command :h3
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[Syntax:]
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pair_style soft cutoff :pre
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cutoff = global cutoff for soft interactions (distance units) :ul
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[Examples:]
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pair_style soft 2.5
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pair_coeff * * 0.0 60.0
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pair_coeff 1 1 0.0 60.0 3.0 :pre
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[Description:]
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Style {soft} computes pairwise interactions with the formula
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:c,image(Eqs/pair_soft.jpg)
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It is useful for pushing apart overlapping atoms, since it does not
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blow up as r goes to 0. A is a pre-factor that varies in time from
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the start to the end of the run. The "run"_run.html command documents
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how to make the ramping take place across multiple runs. Rc is the
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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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Astart (energy units)
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Astop (energy units)
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cutoff (distance units) :ul
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Astart and Astop are the values of the prefactor at the start and end
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of the next run. At intermediate times the value of A will be ramped
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between these 2 values. Note that before performing a 2nd run, you
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will want to adjust the values of Astart and Astop for all type pairs,
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or switch to a new pair style.
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The last coefficient is optional. If not specified, the global soft
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cutoff is used.
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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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