forked from lijiext/lammps
113 lines
3.4 KiB
Plaintext
113 lines
3.4 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 lj96/cut command :h3
|
|
pair_style lj96/cut/gpu command :h3
|
|
|
|
[Syntax:]
|
|
|
|
pair_style style cutoff :pre
|
|
|
|
style = {lj96/cut} or {lj96/cut/gpu}
|
|
cutoff = global cutoff for lj96/cut interactions (distance units) :ul
|
|
|
|
[Examples:]
|
|
|
|
pair_style lj96/cut 2.5
|
|
pair_style lj96/cut/gpu 2.5
|
|
pair_coeff * * 1.0 1.0 4.0
|
|
pair_coeff 1 1 1.0 1.0 :pre
|
|
|
|
[Description:]
|
|
|
|
The {lj96/cut} style compute a 9/6 Lennard-Jones potential, instead
|
|
of the standard 12/6 potential, given by
|
|
|
|
:c,image(Eqs/pair_lj96.jpg)
|
|
|
|
Rc is the cutoff.
|
|
|
|
Style {lj96/cut/gpu} is a GPU-enabled version of style {lj96/cut}.
|
|
See more details below.
|
|
|
|
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, or by mixing as described below:
|
|
|
|
epsilon (energy units)
|
|
sigma (distance units)
|
|
cutoff (distance units) :ul
|
|
|
|
The last coefficient is optional. If not specified, the global LJ
|
|
cutoff specified in the pair_style command is used.
|
|
|
|
:line
|
|
|
|
The {lj96/cut/gpu} style is identical to the {lj96/cut} style, except that
|
|
each processor off-loads its pairwise calculations to a
|
|
GPU chip. Depending on the hardware available on your system this can provide a
|
|
speed-up. See the "Running on GPUs"_Section_start.html#2_8 section of
|
|
the manual for more details about hardware and software requirements
|
|
for using GPUs.
|
|
|
|
More details about these settings and various possible hardware
|
|
configuration are in "this section"_Section_start.html#2_8 of the
|
|
manual.
|
|
|
|
Additional requirements in your input script to run with the {lj96/cut/gpu}
|
|
style are as follows:
|
|
|
|
The "newton pair"_newton.html setting must be {off} and
|
|
"fix gpu"_fix_gpu.html must be used. The fix controls the
|
|
essential GPU selection and initialization steps
|
|
|
|
:line
|
|
|
|
[Mixing, shift, table, tail correction, restart, rRESPA info]:
|
|
|
|
For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
|
and cutoff distance for all of the lj/cut pair styles can be mixed.
|
|
The default mix value is {geometric}. See the "pair_modify" command
|
|
for details.
|
|
|
|
This pair style supports the "pair_modify"_pair_modify.html shift
|
|
option for the energy of the pair interaction.
|
|
|
|
The "pair_modify"_pair_modify.html table option is not relevant
|
|
for this pair style.
|
|
|
|
This pair style supports the "pair_modify"_pair_modify.html tail
|
|
option for adding a long-range tail correction to the energy and
|
|
pressure of the pair interaction.
|
|
|
|
This pair style writes its information to "binary restart
|
|
files"_restart.html, so pair_style and pair_coeff commands do not need
|
|
to be specified in an input script that reads a restart file.
|
|
|
|
This pair style supports the use of the {inner}, {middle}, and {outer}
|
|
keywords of the "run_style respa"_run_style.html command, meaning the
|
|
pairwise forces can be partitioned by distance at different levels of
|
|
the rRESPA hierarchy. See the "run_style"_run_style.html command for
|
|
details.
|
|
|
|
:line
|
|
|
|
[Restrictions:]
|
|
|
|
The {lj96/cut/gpu} style is part of the "gpu" package. It
|
|
is only enabled if LAMMPS is built with this packages. See the
|
|
"Making LAMMPS"_Section_start.html#2_3 section for more info.
|
|
|
|
[Related commands:]
|
|
|
|
"pair_coeff"_pair_coeff.html
|
|
|
|
[Default:] none
|