2006-09-22 00:22:34 +08:00
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<HTML>
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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
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<HR>
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<H3>pair_style command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>pair_style style args
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</PRE>
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2007-10-03 06:56:45 +08:00
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<UL><LI>style = one of the styles from the list below
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2006-09-22 00:22:34 +08:00
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<LI>args = arguments used by a particular style
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>pair_style lj/cut 2.5
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pair_style eam/alloy
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pair_style hybrid lj/charmm/coul/long 10.0 eam
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pair_style table linear 1000
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pair_style none
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Set the formula(s) LAMMPS uses to compute pairwise interactions. In
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LAMMPS, pair potentials are defined between pairs of atoms that are
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within a cutoff distance and the set of active interactions typically
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changes over time. See the <A HREF = "bond_style.html">bond_style</A> command to
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define potentials between pairs of bonded atoms, which typically
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remain in place for the duration of a simulation.
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</P>
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<P>In LAMMPS, pairwise force fields encompass a variety of interactions,
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some of which include many-body effects, e.g. EAM, Stillinger-Weber,
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2007-06-20 20:56:17 +08:00
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Tersoff, REBO potentials. They are still classified as "pairwise"
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potentials because the set of interacting atoms changes with time
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2007-06-25 22:36:36 +08:00
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(unlike molecular bonds) and thus a neighbor list is used to find
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2006-11-29 01:00:29 +08:00
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nearby interacting atoms.
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2006-09-22 00:22:34 +08:00
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</P>
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<P>Hybrid models where specified pairs of atom types interact via
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different pair potentials can be setup using the <I>hybrid</I> pair style.
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</P>
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<P>The coefficients associated with a pair style are typically set for
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each pair of atom types, and are specified by the
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<A HREF = "pair_coeff.html">pair_coeff</A> command or read from a file by the
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<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
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2007-06-25 22:36:36 +08:00
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commands.
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</P>
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<P>The <A HREF = "pair_modify.html">pair_modify</A> command sets options for mixing of
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type I-J interaction coefficients and adding energy offsets or tail
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corrections to Lennard-Jones potentials. Details on these options as
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they pertain to individual potentials are described on the doc page
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for the potential. Likewise, info on whether the potential
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2008-01-22 02:12:34 +08:00
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information is stored in a <A HREF = "write_restart.html">restart file</A> is listed
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on the potential doc page.
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2006-09-22 00:22:34 +08:00
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</P>
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<P>In the formulas listed for each pair style, <I>E</I> is the energy of a
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pairwise interaction between two atoms separated by a distance <I>r</I>.
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The force between the atoms is the negative derivative of this
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expression.
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</P>
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<P>If the pair_style command has a cutoff argument, it sets global
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cutoffs for all pairs of atom types. The distance(s) can be smaller
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or larger than the dimensions of the simulation box.
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</P>
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<P>Typically, the global cutoff value can be overridden for a specific
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pair of atom types by the <A HREF = "pair_coeff.html">pair_coeff</A> command. The
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pair style settings (including global cutoffs) can be changed by a
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subsequent pair_style command using the same style. This will reset
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the cutoffs for all atom type pairs, including those previously set
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explicitly by a <A HREF = "pair_coeff.html">pair_coeff</A> command. The exceptions
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to this are that pair_style <I>table</I> and <I>hybrid</I> settings cannot be
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reset. A new pair_style command for these styles will wipe out all
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previously specified pair_coeff values.
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</P>
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<HR>
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<P>Here is an alphabetic list of pair styles defined in LAMMPS. Click on
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the style to display the formula it computes, arguments specified in
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the pair_style command, and coefficients specified by the associated
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2012-04-06 22:28:14 +08:00
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<A HREF = "pair_coeff.html">pair_coeff</A> command.
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</P>
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<P>Note that there are also additional pair styles submitted by users
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which are included in the LAMMPS distribution. The list of these with
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links to the individual styles are given in the pair section of <A HREF = "Section_commands.html#cmd_5">this
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page</A>.
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</P>
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<P>There are also additional accelerated pair styles included in the
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LAMMPS distribution for faster performance on CPUs and GPUs. The list
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of these with links to the individual styles are given in the pair
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section of <A HREF = "Section_commands.html#cmd_5">this page</A>.
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2006-09-22 00:22:34 +08:00
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</P>
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2007-02-10 05:37:30 +08:00
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<UL><LI><A HREF = "pair_none.html">pair_style none</A> - turn off pairwise interactions
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2009-11-05 06:12:52 +08:00
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<LI><A HREF = "pair_hybrid.html">pair_style hybrid</A> - multiple styles of pairwise interactions
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<LI><A HREF = "pair_hybrid.html">pair_style hybrid/overlay</A> - multiple styles of superposed pairwise interactions
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2006-09-22 00:22:34 +08:00
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</UL>
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2011-06-09 04:56:17 +08:00
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<UL><LI><A HREF = "pair_adp.html">pair_style adp</A> - angular dependent potential (ADP) of Mishin
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<LI><A HREF = "pair_airebo.html">pair_style airebo</A> - AIREBO potential of Stuart
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2012-06-26 06:22:46 +08:00
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<LI><A HREF = "pair_bop.html">pair_style bop</A> - BOP potential of Pettifor
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2010-10-08 05:20:45 +08:00
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<LI><A HREF = "pair_born.html">pair_style born</A> - Born-Mayer-Huggins potential
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2011-12-13 23:56:58 +08:00
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<LI><A HREF = "pair_born.html">pair_style born/coul/long</A> - Born-Mayer-Huggins with long-range Coulombics
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<LI><A HREF = "pair_born.html">pair_style born/coul/wolf</A> - Born-Mayer-Huggins with Coulombics via Wolf potential
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2011-10-25 01:46:47 +08:00
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<LI><A HREF = "pair_brownian.html">pair_style brownian</A> - Brownian potential for Fast Lubrication Dynamics
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<LI><A HREF = "pair_brownian.html">pair_style brownian/poly</A> - Brownian potential for Fast Lubrication Dynamics with polydispersity
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2007-06-25 22:36:36 +08:00
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<LI><A HREF = "pair_buck.html">pair_style buck</A> - Buckingham potential
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2008-03-01 09:13:20 +08:00
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<LI><A HREF = "pair_buck.html">pair_style buck/coul/cut</A> - Buckingham with cutoff Coulomb
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_buck.html">pair_style buck/coul/long</A> - Buckingham with long-range Coulomb
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2007-06-20 20:56:17 +08:00
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<LI><A HREF = "pair_colloid.html">pair_style colloid</A> - integrated colloidal potential
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2011-10-26 22:11:00 +08:00
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<LI><A HREF = "pair_comb.html">pair_style comb</A> - charge-optimized many-body (COMB) potential
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2007-10-03 05:55:02 +08:00
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<LI><A HREF = "pair_coul.html">pair_style coul/cut</A> - cutoff Coulombic potential
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2008-03-01 09:13:20 +08:00
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<LI><A HREF = "pair_coul.html">pair_style coul/debye</A> - cutoff Coulombic potential with Debye screening
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2007-10-03 05:55:02 +08:00
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<LI><A HREF = "pair_coul.html">pair_style coul/long</A> - long-range Coulombic potential
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2011-12-13 23:56:58 +08:00
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<LI><A HREF = "pair_coul.html">pair_style coul/wolf</A> - Coulombics via Wolf potential
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2008-09-26 23:13:52 +08:00
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<LI><A HREF = "pair_dipole.html">pair_style dipole/cut</A> - point dipoles with cutoff
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_dpd.html">pair_style dpd</A> - dissipative particle dynamics (DPD)
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2010-05-06 22:37:29 +08:00
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<LI><A HREF = "pair_dpd.html">pair_style dpd/tstat</A> - DPD thermostatting
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2009-11-07 01:05:06 +08:00
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<LI><A HREF = "pair_dsmc.html">pair_style dsmc</A> - Direct Simulation Monte Carlo (DSMC)
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_eam.html">pair_style eam</A> - embedded atom method (EAM)
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<LI><A HREF = "pair_eam.html">pair_style eam/alloy</A> - alloy EAM
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<LI><A HREF = "pair_eam.html">pair_style eam/fs</A> - Finnis-Sinclair EAM
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2010-09-01 08:31:09 +08:00
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<LI><A HREF = "pair_eim.html">pair_style eim</A> - embedded ion method (EIM)
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2010-10-08 05:20:45 +08:00
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<LI><A HREF = "pair_gauss.html">pair_style gauss</A> - Gaussian potential
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2007-04-20 07:25:27 +08:00
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<LI><A HREF = "pair_gayberne.html">pair_style gayberne</A> - Gay-Berne ellipsoidal potential
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2009-01-09 08:14:52 +08:00
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<LI><A HREF = "pair_gran.html">pair_style gran/hertz/history</A> - granular potential with Hertzian interactions
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<LI><A HREF = "pair_gran.html">pair_style gran/hooke</A> - granular potential with history effects
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<LI><A HREF = "pair_gran.html">pair_style gran/hooke/history</A> - granular potential without history effects
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2010-10-26 04:29:55 +08:00
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<LI><A HREF = "pair_hbond_dreiding.html">pair_style hbond/dreiding/lj</A> - DREIDING hydrogen bonding LJ potential
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<LI><A HREF = "pair_hbond_dreiding.html">pair_style hbond/dreiding/morse</A> - DREIDING hydrogen bonding Morse potential
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2012-05-22 23:00:11 +08:00
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<LI><A HREF = "pair_lcbop.html">pair_style lcbop</A> - long-range bond-order potential (LCBOP)
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2011-10-20 23:06:55 +08:00
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<LI><A HREF = "pair_line_lj.html">pair_style line/lj</A> - LJ potential between line segments
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/charmm</A> - CHARMM potential with cutoff Coulomb
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<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/charmm/implicit</A> - CHARMM for implicit solvent
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<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/long</A> - CHARMM with long-range Coulomb
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<LI><A HREF = "pair_class2.html">pair_style lj/class2</A> - COMPASS (class 2) force field with no Coulomb
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<LI><A HREF = "pair_class2.html">pair_style lj/class2/coul/cut</A> - COMPASS with cutoff Coulomb
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<LI><A HREF = "pair_class2.html">pair_style lj/class2/coul/long</A> - COMPASS with long-range Coulomb
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<LI><A HREF = "pair_lj.html">pair_style lj/cut</A> - cutoff Lennard-Jones potential with no Coulomb
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<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/cut</A> - LJ with cutoff Coulomb
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2008-03-01 09:13:20 +08:00
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<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/debye</A> - LJ with Debye screening added to Coulomb
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/long</A> - LJ with long-range Coulomb
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<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/long/tip4p</A> - LJ with long-range Coulomb for TIP4P water
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<LI><A HREF = "pair_lj_expand.html">pair_style lj/expand</A> - Lennard-Jones for variable size particles
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2008-05-16 04:48:06 +08:00
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<LI><A HREF = "pair_gromacs.html">pair_style lj/gromacs</A> - GROMACS-style Lennard-Jones potential
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<LI><A HREF = "pair_gromacs.html">pair_style lj/gromacs/coul/gromacs</A> - GROMACS-style LJ and Coulombic potential
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_lj_smooth.html">pair_style lj/smooth</A> - smoothed Lennard-Jones potential
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2012-01-10 01:49:15 +08:00
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<LI><A HREF = "pair_lj_smooth_linear.html">pair_style lj/smooth/linear</A> - linear smoothed Lennard-Jones potential
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2011-06-23 21:40:07 +08:00
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<LI><A HREF = "pair_lj96.html">pair_style lj96/cut</A> - Lennard-Jones 9/6 potential
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2007-10-12 07:52:34 +08:00
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<LI><A HREF = "pair_lubricate.html">pair_style lubricate</A> - hydrodynamic lubrication forces
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2011-10-25 01:46:47 +08:00
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<LI><A HREF = "pair_lubricate.html">pair_style lubricate/poly</A> - hydrodynamic lubrication forces with polydispersity
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<LI><A HREF = "pair_lubricateU.html">pair_style lubricateU</A> - hydrodynamic lubrication forces for Fast Lubrication Dynamics
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<LI><A HREF = "pair_lubricateU.html">pair_style lubricateU/poly</A> - hydrodynamic lubrication forces for Fast Lubrication with polydispersity
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_meam.html">pair_style meam</A> - modified embedded atom method (MEAM)
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2012-11-15 06:50:11 +08:00
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<LI><A HREF = "pair_mie.html">pair_style mie</A> - Mie potential
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_morse.html">pair_style morse</A> - Morse potential
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2010-08-09 22:09:03 +08:00
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<LI><A HREF = "pair_peri.html">pair_style peri/lps</A> - peridynamic LPS potential
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<LI><A HREF = "pair_peri.html">pair_style peri/pmb</A> - peridynamic PMB potential
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2009-02-07 00:12:07 +08:00
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<LI><A HREF = "pair_reax.html">pair_style reax</A> - ReaxFF potential
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2011-06-08 00:57:45 +08:00
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<LI><A HREF = "pair_airebo.html">pair_style rebo</A> - 2nd generation REBO potential of Brenner
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2007-10-23 05:43:55 +08:00
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<LI><A HREF = "pair_resquared.html">pair_style resquared</A> - Everaers RE-Squared ellipsoidal potential
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2007-02-10 05:37:30 +08:00
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<LI><A HREF = "pair_soft.html">pair_style soft</A> - Soft (cosine) potential
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<LI><A HREF = "pair_sw.html">pair_style sw</A> - Stillinger-Weber 3-body potential
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<LI><A HREF = "pair_table.html">pair_style table</A> - tabulated pair potential
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<LI><A HREF = "pair_tersoff.html">pair_style tersoff</A> - Tersoff 3-body potential
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2009-11-07 06:39:50 +08:00
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<LI><A HREF = "pair_tersoff_zbl.html">pair_style tersoff/zbl</A> - Tersoff/ZBL 3-body potential
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2011-10-20 23:06:55 +08:00
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<LI><A HREF = "pair_tri_lj.html">pair_style tri/lj</A> - LJ potential between triangles
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2009-11-07 05:01:28 +08:00
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<LI><A HREF = "pair_yukawa.html">pair_style yukawa</A> - Yukawa potential
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<LI><A HREF = "pair_yukawa_colloid.html">pair_style yukawa/colloid</A> - screened Yukawa potential for finite-size particles
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2006-09-22 00:22:34 +08:00
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</UL>
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<HR>
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<P><B>Restrictions:</B>
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</P>
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<P>This command must be used before any coefficients are set by the
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<A HREF = "pair_coeff.html">pair_coeff</A>, <A HREF = "read_data.html">read_data</A>, or
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<A HREF = "read_restart.html">read_restart</A> commands.
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</P>
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<P>Some pair styles are part of specific packages. They are only enabled
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2011-08-26 00:46:23 +08:00
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if LAMMPS was built with that package. See the <A HREF = "Section_start.html#start_3">Making
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LAMMPS</A> section for more info on packages.
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The doc pages for individual pair potentials tell if it is part of a
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2007-06-25 22:36:36 +08:00
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package.
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2006-09-22 00:22:34 +08:00
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "pair_coeff.html">pair_coeff</A>, <A HREF = "read_data.html">read_data</A>,
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<A HREF = "pair_modify.html">pair_modify</A>, <A HREF = "kspace_style.html">kspace_style</A>,
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<A HREF = "dielectric.html">dielectric</A>, <A HREF = "pair_write.html">pair_write</A>
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</P>
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<P><B>Default:</B>
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</P>
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<PRE>pair_style none
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</PRE>
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</HTML>
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