LAMMPS is a classical molecular dynamics code, and an acronym for
Large-scale Atomic/Molecular Massively Parallel Simulator.
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
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
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. Periodic releases are also available on
(6/12) Added a static and dynamic load
balance via the balance and fix
balance commands, for use with problems where
particles do not fill the simulation box uniformly.
(6/12) Added rerun and
read_dump commands to allow dump files to be
reprocessed by LAMMPS.
(5/12) Added a USER-COLVARS package and
fix colvars command to interface LAMMPS to an
open-source collective variables package for the calculation of
potentials of mean force (PMFs) in various scenarios.
(see the Pictures and
Movies pages for more examples of LAMMPS
This is work by Sergey Zybin (zybin at wag.caltech.edu) and
collaborators at Caltech to model shock-induced instabilities in
explosive materials which have heterogeneous features, such as defects
or interfaces, using the ReaxFF force field.
The figure shows shock loading of PBX in a 3.6M atom model with a
saw-tooth interface between RDX and its polymer binder. The color
represents slip which is highest at the interface.
This paper has further details:
Elucidation of the dynamics for hot-spot initiation at nonuniform
interfaces of highly shocked materials, Qi An, Sergey V. Zybin,
William A. Goddard III, Andres Jaramillo-Botero, Mario Blanco, and
Sheng-Nian Luo, Phys Rev B, 84, 220101 (2011).