"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)

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pair_style sph/lj command :h3

[Syntax:]

pair_style sph/lj :pre

[Examples:]

pair_style sph/lj
pair_coeff * * 1.0 2.4 :pre

[Description:]

The sph/lj style computes pressure forces between particles according
to the Lennard-Jones equation of state, which is computed according to
Ree's 1980 polynomial fit "(Ree)"_#Ree. The Lennard-Jones parameters
epsilon and sigma are set to unity.  This pair style also computes
Monaghan's artificial viscosity to prevent particles from
interpenetrating "(Monaghan)"_#Monoghan.

See "this PDF guide"_USER/sph/SPH_LAMMPS_userguide.pdf to using SPH in
LAMMPS.

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.

nu artificial viscosity (no units)
h kernel function cutoff (distance units) :ul

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[Mixing, shift, table, tail correction, restart, rRESPA info]:

This style does not support mixing.  Thus, coefficients for all
I,J pairs must be specified explicitly.

This style does not support the "pair_modify"_pair_modify.html
shift, table, and tail options.

This style does not write information to "binary restart
files"_restart.html.  Thus, you need to re-specify the pair_style and
pair_coeff commands in an input script that reads a restart file.

This style can only be used via the {pair} keyword of the "run_style
respa"_run_style.html command.  It does not support the {inner},
{middle}, {outer} keywords.

[Restrictions:]

As noted above, the Lennard-Jones parameters epsilon and sigma are set
to unity.

This pair style is part of the USER-SPH package.  It is only enabled
if LAMMPS was built with that package.  See the "Build
package"_Build_package.html doc page for more info.

[Related commands:]

"pair_coeff"_pair_coeff.html, pair_sph/rhosum

[Default:] none

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:link(Ree)
[(Ree)] Ree, Journal of Chemical Physics, 73, 5401 (1980).

:link(Monoghan)
[(Monaghan)] Monaghan and Gingold, Journal of Computational Physics,
52, 374-389 (1983).
