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lammps/doc/src/pair_lj96.rst

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.. index:: pair_style lj96/cut
.. index:: pair_style lj96/cut/gpu
.. index:: pair_style lj96/cut/omp
pair_style lj96/cut command
===========================
Accelerator Variants: *lj96/cut/gpu*, *lj96/cut/omp*
Syntax
""""""
.. code-block:: LAMMPS
pair_style lj96/cut cutoff
* cutoff = global cutoff for lj96/cut interactions (distance units)
Examples
""""""""
.. code-block:: LAMMPS
pair_style lj96/cut 2.5
pair_coeff * * 1.0 1.0 4.0
pair_coeff 1 1 1.0 1.0
Description
"""""""""""
The *lj96/cut* style compute a 9/6 Lennard-Jones potential, instead
of the standard 12/6 potential, given by
.. math::
E = 4 \epsilon \left[ \left(\frac{\sigma}{r}\right)^{9} -
\left(\frac{\sigma}{r}\right)^6 \right]
\qquad r < r_c
:math:`r_c` is the cutoff.
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, or in the data file or restart files read by the
:doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
commands, or by mixing as described below:
* :math:`\epsilon` (energy units)
* :math:`\sigma` (distance units)
* cutoff (distance units)
The last coefficient is optional. If not specified, the global LJ
cutoff specified in the pair_style command is used.
----------
.. include:: accel_styles.rst
----------
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 :doc:`pair_modify <pair_modify>` shift
option for the energy of the pair interaction.
The :doc:`pair_modify <pair_modify>` table option is not relevant
for this pair style.
This pair style supports the :doc:`pair_modify <pair_modify>` 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 :doc:`binary restart files <restart>`, 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 :doc:`run_style respa <run_style>` command, meaning the
pairwise forces can be partitioned by distance at different levels of
the rRESPA hierarchy. See the :doc:`run_style <run_style>` command for
details.
----------
Restrictions
""""""""""""
This pair style is part of the EXTRA-PAIR package. It is only enabled if
LAMMPS was built with that package. See the
:doc:`Build package <Build_package>` page for more info.
Related commands
""""""""""""""""
:doc:`pair_coeff <pair_coeff>`
Default
"""""""
none