This is the home page for the classical molecular dynamics code LAMMPS, an acronym for Large-scale Atomic/Molecular Massively Parallel Simulator. The current version of LAMMPS is 15 Jan 2010.

LAMMPS has potentials for soft materials (biomolecules, polymers) and solid-state materials (metals, semiconductors) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale.

LAMMPS runs on single processors or in parallel using message-passing techniques and a spatial-decomposition of the simulation domain. The code is designed to be easy to modify or extend with new functionality.

LAMMPS is distributed as an open source code under the terms of the GPL. The current version can be downloaded here. Links are also included to older F90/F77 versions. The last major release is also available on SourceForge.

LAMMPS is distributed by Sandia National Laboratories, a US Department of Energy laboratory. The main authors of LAMMPS are listed on this page along with contact info and other contributors. Funding for LAMMPS development has come primarily from DOE (OASCR, OBER, ASCI, LDRD, Genomes-to-Life) and is acknowledged here.

• (1/10) Release of 15 Jan 2010 version of LAMMPS. New commands or new options on existing commands include Nose/Hoover chains in fix nvt, angle_style table, atom_modify sort, atom_style colloid, bond_style table, communicate vel, compute angle/local, compute bond/local, compute com, compute com/molecule, compute dihedral/local, compute gyration, compute gyration/molecule, compute improper/local, compute msd, compute msd/molecule, compute pair/local, compute property/atom, compute property/local, compute property/molecule, compute rdf, dump cfg, dump local, dynamic regions, fix ave/histo, fix move, fix store/coord, fix store/force, fix wall/colloid, fix wall/harmonic, fix wall/region, min_style htfn, pair_style dsmc, pair_style gayberne/gpu, pair_style lj/cut/gpu, pair_style lj96/cut, pair_style yukawa/colloid, prd, user atc package, user cd-eam package, user-imd package. See details here.
• (11/09) Added SourceForge mail list archives to LAMMPS mail list page, so they can be more easily browsed and searched.
• (11/09) Real-time visualization by hooking LAMMPS to VMD via a socket connection. See the fix imd command.
• (10/09) Added first accelerated dynamics technique to LAMMPS, namely the parallel replica dynamics (PRD) method of Art Voter, which can be invoked via the prd commmand.
• (10/09) Added a pre-built Windows executable for LAMMPS to the download page.
• (9/09) Addition of an atomic-to-continuum package for performing simulations that couple continuum finite elements to atoms.
• (8/09) Addition of first GPU-enabled pair_styles: pair_style lj/cut/gpu and pair_style gayberne/gpu.
• (7/09) Release of 7 Jul 2009 version of LAMMPS. Enhanced features include improvements to the energy minimizer, per-type and per-atom mass and size/shape, self-documenting format for dump files, and a more general fix rigid allowing for rigid bodies containing finite-size particles. New commands or new options on existing commands include compute heat/flux for Green-Kubo thermal conductivity, compute cna/atom, pair_style reax, fix box/relax, group delete, fix deform wiggle, fix evaporate, fix ttm, compute reduce/region, compute temp/profile, pair_style born/coul/long, and fix reax/bonds. See details here.
• (2/09) Addition of ReaxFF potentials with new pair_style reax command.
• (1/09) Release of 9 Jan 2009 version of LAMMPS. New features include a reworking of how variables and computes keep track of when they were invoked so as to be current between simulation runs, a new Peridynamics package for mesoscale modeling, auto-adjusting of the PPPM stencil when large numbers of processors are used, and an upgrade to the Hertzian granular pair_style for polydisperse systems. New commands or new command options include communicate cutoff, pair_style tersoff/zbl, fix indent plane fix wall/lj93 velocity, delete_atoms porosity, special_bonds options, fix bond/create, and fix bond/break. See details here.
• Old

This is work by Reese Jones (rjones at sandia.gov), Jeremy Templeton (jatempl at sandia.gov), and Jon Zimmerman (jzimmer at sandia.gov) at Sandia using their ATC package to couple finite element (FE) and molecular dynamics (MD) calculations. The package creates a FE mesh and passes information back and forth between the MD and FE representations of the problem each timestep.

The figures show (left to right):

• Electron/transport enhanced simulation of heating and deformation of a metallic carbon nanotube
• Compressive stress field for an atomic simulation of shock loading
• Atomic (left) and Continuum (right) displacement fields for a stretched, center-cracked body
• 1st Piola-Kirchhoff (left) and Cauchy (right) stress fields for a stretched, center-cracked body

The doc page for the fix atc command has further details and cites these 2 papers:

An atomistic-to-continuum coupling method for heat transfer in solids, G. J. Wagner, R. E. Jones, J. A. Templeton, and M. L. Parks, Special Issue of Computer Methods and Applied Mechanics, 197, 3351-3365 (2008). (abstract)

Calculation of stress in atomistic simulation, J. A. Zimmerman, E. B. Webb III, J. J. Hoyt, R. E. Jones, P. A. Klein, and D. J. Bammann, Special Issue of Modelling and Simulation in Materials Science and Engineering, 12, S319 (2004). (abstract)