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pair_sph_lj.txt
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.. index:: pair_style sph/lj
pair_style sph/lj command
=========================
Syntax
""""""
.. parsed-literal::
pair_style sph/lj
Examples
""""""""
.. parsed-literal::
pair_style sph/lj
pair_coeff * * 1.0 2.4
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 :ref:`(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
interpentrating :ref:`(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 :doc:`pair_coeff <pair_coeff>` command as in the examples
above.
* nu artificial viscosity (no units)
* h kernel function cutoff (distance units)
----------
**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 :doc:`pair_modify <pair_modify>`
shift, table, and tail options.
This style does not write information to :doc:`binary restart files <restart>`. 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 :doc:`run_style respa <run_style>` 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 :ref:`Making LAMMPS <start_3>` section for more info.
Related commands
""""""""""""""""
:doc:`pair_coeff <pair_coeff>`, pair_sph/rhosum
**Default:** none
----------
.. _Ree:
**(Ree)** Ree, Journal of Chemical Physics, 73, 5401 (1980).
.. _Monoghan:
**(Monaghan)** Monaghan and Gingold, Journal of Computational Physics,
52, 374-389 (1983).
.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html
.. _lc: Section_commands.html#comm
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