forked from lijiext/lammps
129 lines
3.6 KiB
Plaintext
129 lines
3.6 KiB
Plaintext
.. index:: pair_style lj96/cut
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pair_style lj96/cut command
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===========================
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pair_style lj96/cut/cuda command
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================================
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pair_style lj96/cut/gpu command
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===============================
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pair_style lj96/cut/omp command
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===============================
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Syntax
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""""""
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.. parsed-literal::
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pair_style lj96/cut cutoff
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* cutoff = global cutoff for lj96/cut interactions (distance units)
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Examples
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""""""""
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.. parsed-literal::
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pair_style lj96/cut 2.5
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pair_coeff * * 1.0 1.0 4.0
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pair_coeff 1 1 1.0 1.0
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Description
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"""""""""""
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The *lj96/cut* style compute a 9/6 Lennard-Jones potential, instead
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of the standard 12/6 potential, given by
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.. image:: Eqs/pair_lj96.jpg
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:align: center
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Rc is the cutoff.
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The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above, or in the data file or restart files read by the
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:doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
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commands, or by mixing as described below:
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* epsilon (energy units)
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* sigma (distance units)
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* cutoff (distance units)
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The last coefficient is optional. If not specified, the global LJ
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cutoff specified in the pair_style command is used.
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----------
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Styles with a *cuda*, *gpu*, *intel*, *kk*, *omp*, or *opt* suffix are
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functionally the same as the corresponding style without the suffix.
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They have been optimized to run faster, depending on your available
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hardware, as discussed in :doc:`Section_accelerate <Section_accelerate>`
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of the manual. The accelerated styles take the same arguments and
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should produce the same results, except for round-off and precision
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issues.
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These accelerated styles are part of the USER-CUDA, GPU, USER-INTEL,
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KOKKOS, USER-OMP and OPT packages, respectively. They are only
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enabled if LAMMPS was built with those packages. See the :ref:`Making LAMMPS <start_3>` section for more info.
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You can specify the accelerated styles explicitly in your input script
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by including their suffix, or you can use the :ref:`-suffix command-line switch <start_7>` when you invoke LAMMPS, or you can
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use the :doc:`suffix <suffix>` command in your input script.
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See :doc:`Section_accelerate <Section_accelerate>` of the manual for
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more instructions on how to use the accelerated styles effectively.
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----------
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**Mixing, shift, table, tail correction, restart, rRESPA info**:
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For atom type pairs I,J and I != J, the epsilon and sigma coefficients
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and cutoff distance for all of the lj/cut pair styles can be mixed.
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The default mix value is *geometric*. See the "pair_modify" command
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for details.
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This pair style supports the :doc:`pair_modify <pair_modify>` shift
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option for the energy of the pair interaction.
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The :doc:`pair_modify <pair_modify>` table option is not relevant
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for this pair style.
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This pair style supports the :doc:`pair_modify <pair_modify>` tail
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option for adding a long-range tail correction to the energy and
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pressure of the pair interaction.
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This pair style writes its information to :doc:`binary restart files <restart>`, so pair_style and pair_coeff commands do not need
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to be specified in an input script that reads a restart file.
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This pair style supports the use of the *inner*, *middle*, and *outer*
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keywords of the :doc:`run_style respa <run_style>` command, meaning the
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pairwise forces can be partitioned by distance at different levels of
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the rRESPA hierarchy. See the :doc:`run_style <run_style>` command for
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details.
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----------
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Restrictions
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""""""""""""
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none
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Related commands
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""""""""""""""""
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:doc:`pair_coeff <pair_coeff>`
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**Default:** none
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.. _lws: http://lammps.sandia.gov
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.. _ld: Manual.html
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.. _lc: Section_commands.html#comm
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