.. index:: pair_style lj/sf pair_style lj/sf command ======================== pair_style lj/sf/omp command ============================ Syntax """""" .. parsed-literal:: pair_style lj/sf cutoff * cutoff = global cutoff for Lennard-Jones interactions (distance units) Examples """""""" .. parsed-literal:: pair_style lj/sf 2.5 pair_coeff * * 1.0 1.0 pair_coeff 1 1 1.0 1.0 3.0 Description """"""""""" Style *lj/sf* computes a truncated and force-shifted LJ interaction (Shifted Force Lennard-Jones), so that both the potential and the force go continuously to zero at the cutoff :ref:`(Toxvaerd) `: .. image:: Eqs/pair_lj_sf.jpg :align: center The following coefficients must be defined for each pair of atoms types via the :doc:`pair_coeff ` command as in the examples above, or in the data file or restart files read by the :doc:`read_data ` or :doc:`read_restart ` commands, or by mixing as described below: * epsilon (energy units) * 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. ---------- Styles with a *cuda*\ , *gpu*\ , *intel*\ , *kk*\ , *omp*\ , or *opt* suffix are functionally the same as the corresponding style without the suffix. They have been optimized to run faster, depending on your available hardware, as discussed in :doc:`Section_accelerate ` of the manual. The accelerated styles take the same arguments and should produce the same results, except for round-off and precision issues. These accelerated styles are part of the USER-CUDA, GPU, USER-INTEL, KOKKOS, USER-OMP and OPT packages, respectively. They are only enabled if LAMMPS was built with those packages. See the :ref:`Making LAMMPS ` section for more info. You can specify the accelerated styles explicitly in your input script by including their suffix, or you can use the :ref:`-suffix command-line switch ` when you invoke LAMMPS, or you can use the :doc:`suffix ` command in your input script. See :doc:`Section_accelerate ` of the manual for more instructions on how to use the accelerated styles effectively. ---------- **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 this pair style can be mixed. Rin is a cutoff value and is mixed like the cutoff. The default mix value is *geometric*\ . See the "pair_modify" command for details. The :doc:`pair_modify ` shift option is not relevant for this pair style, since the pair interaction goes to 0.0 at the cutoff. The :doc:`pair_modify ` table option is not relevant for this pair style. This pair style does not support the :doc:`pair_modify ` tail option for adding long-range tail corrections to energy and pressure, since the energy of the pair interaction is smoothed to 0.0 at the cutoff. This pair style writes its information to :doc:`binary restart files `, 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 can only be used via the *pair* keyword of the :doc:`run_style respa ` command. It does not support the *inner*\ , *middle*\ , *outer* keywords. ---------- Restrictions """""""""""" This pair style is part of the USER-MISC package. It is only enabled if LAMMPS was built with that package. See the :ref:`Making LAMMPS ` section for more info. Related commands """""""""""""""" :doc:`pair_coeff ` **Default:** none ---------- .. _Toxvaerd: **(Toxvaerd)** Toxvaerd, Dyre, J Chem Phys, 134, 081102 (2011). .. _lws: http://lammps.sandia.gov .. _ld: Manual.html .. _lc: Section_commands.html#comm