forked from lijiext/lammps
122 lines
3.6 KiB
Plaintext
122 lines
3.6 KiB
Plaintext
.. index:: pair_style lj/smooth/linear
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pair_style lj/smooth/linear command
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===================================
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pair_style lj/smooth/linear/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 lj/smooth/linear Rc
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* Rc = cutoff for lj/smooth/linear interactions (distance units)
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Examples
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""""""""
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.. parsed-literal::
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pair_style lj/smooth/linear 5.456108274435118
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pair_coeff * * 0.7242785984051078 2.598146797350056
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pair_coeff 1 1 20.0 1.3 9.0
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Description
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"""""""""""
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Style *lj/smooth/linear* computes a LJ interaction that combines the
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standard 12/6 Lennard-Jones function and subtracts a linear term that
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includes the cutoff distance Rc, as in this formula:
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.. image:: Eqs/pair_lj_smooth_linear.jpg
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:align: center
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At the cutoff Rc, the energy and force (its 1st derivative) will be 0.0.
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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 value
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for Rc is used.
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----------
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Styles with a *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 GPU, USER-INTEL, KOKKOS,
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USER-OMP and OPT packages, respectively. They are only enabled if
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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 can be mixed. The default mix value is geometric.
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See the "pair_modify" command for details.
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This pair style does not support the :doc:`pair_modify <pair_modify>`
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shift option for the energy of the pair interaction.
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The :doc:`pair_modify <pair_modify>` table option is not relevant for
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this pair style.
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This pair style does not support the :doc:`pair_modify <pair_modify>`
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tail option for adding long-range tail corrections to energy and
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pressure, since the energy of the pair interaction is smoothed to 0.0
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at the cutoff.
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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 can only be used via the *pair* keyword of the
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:doc:`run_style respa <run_style>` command. It does not support the
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*inner*\ , *middle*\ , *outer* keywords.
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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>`, :doc:`pair lj/smooth <pair_lj_smooth>`
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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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