forked from lijiext/lammps
61 lines
1.6 KiB
Plaintext
61 lines
1.6 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
|
|
|
|
:link(lws,http://lammps.sandia.gov)
|
|
:link(ld,Manual.html)
|
|
:link(lc,Section_commands.html#comm)
|
|
|
|
:line
|
|
|
|
pair_style soft command :h3
|
|
|
|
[Syntax:]
|
|
|
|
pair_style soft cutoff :pre
|
|
|
|
cutoff = global cutoff for soft interactions (distance units) :ul
|
|
|
|
[Examples:]
|
|
|
|
pair_style soft 2.5
|
|
pair_coeff * * 0.0 60.0
|
|
pair_coeff 1 1 0.0 60.0 3.0 :pre
|
|
|
|
[Description:]
|
|
|
|
Style {soft} computes pairwise interactions with the formula
|
|
|
|
:c,image(Eqs/pair_soft.jpg)
|
|
|
|
It is useful for pushing apart overlapping atoms, since it does not
|
|
blow up as r goes to 0. A is a pre-factor that varies in time from
|
|
the start to the end of the run. The "run"_run.html command documents
|
|
how to make the ramping take place across multiple runs. Rc is the
|
|
cutoff.
|
|
|
|
The following coefficients must be defined for each pair of atoms
|
|
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
|
above, or in the data file or restart files read by the
|
|
"read_data"_read_data.html or "read_restart"_read_restart.html
|
|
commands:
|
|
|
|
Astart (energy units)
|
|
Astop (energy units)
|
|
cutoff (distance units) :ul
|
|
|
|
Astart and Astop are the values of the prefactor at the start and end
|
|
of the next run. At intermediate times the value of A will be ramped
|
|
between these 2 values. Note that before performing a 2nd run, you
|
|
will want to adjust the values of Astart and Astop for all type pairs,
|
|
or switch to a new pair style.
|
|
|
|
The last coefficient is optional. If not specified, the global soft
|
|
cutoff is used.
|
|
|
|
[Restrictions:] none
|
|
|
|
[Related commands:]
|
|
|
|
"pair_coeff"_pair_coeff.html
|
|
|
|
[Default:] none
|