LAMMPS is a classical molecular dynamics code, and an acronym for
Large-scale Atomic/Molecular Massively Parallel Simulator.
LAMMPS has potentials for solid-state materials (metals,
semiconductors) and soft matter (biomolecules, polymers) 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
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
(3/15) Added a PYTHON package with a
python command which embeds the Python interpreter
in LAMMPS and allows Python code you write to be invoked from a LAMMPS
input script, with data passing back and forth between LAMMPS and
Python. Section_python gives an
(3/15) Added a CORESHELL package with the
capability to run the adiabatic core/shell model for polarization
effects. Section_howto 25 gives an
(1/15) Added a
create_bonds for adding bonds between pairs of
atoms based on a distance criterion.
(1/15) Added a new fix
atom/swap command for performing Monte Carlo
atom swaps (type and charge) either during a dyanmics run or as a
stand-alone MC capability, e.g for surface segregation effects in
(11/14) Added two new options for
performing path-integral molecular dynamics (PIMD) simulations, via
the fix pimd and fix ipi
commands. The former users multiple replicas; the latter wraps LAMMPS
(10/14) Added a src/Make.py
tool to enable one-line builds of
LAMMPS in various configurations, with packages, auxiliary libraries,
and Makefile.machine settings.
(9/14) Significant features added to
LAMMPS in the third quarter of 2014 include use of
create_atoms for irregular shapes specified by
a variable formula, recursive coordinate
bisectioning (RCB) option for the balance and fix
balance commands for effective 3d load
balancing, USER-INTEL package with
optimizations for the Intel Xeon Phi and Intel CPUs, pair
snap, several stand-alone fix
qeq variants for charge equilibration, added
command-line options to specify all
accererator package options at run-time instead of by altering an
input script. See authors here and details
(9/14) Added a QEQ package several new
fix qeq/variant commands. This allows charge
equilibration with any potential that defines charge. It will also
easier development of new pair styles that require charge
(9/14) Added a SNAP package with a
pair_style snap and compute
sna/atom commands for performing expensive but
highly accurate calculations with a potential fit to quantum DFT data.
The pair_style snap doc page has details. A new
potential for Tantalum is provided in the potentials directory.
(8/14) Added a USER-INTEL
package with support for optimizing
several pair styles in either of two modes: vectorization on Intel
CPUs, and offloading computations to Intel coprocessors (Xeon Phis).
This package was written by Mike Brown at Intel, and it can work in
tandem with the USER-OMP package, to
accelerate other portions of the simulation.
(8/14) Added a recursive coordinate
bisectioning (RCB) option to the balance and fix
balance commands, for static and dynamic 3d load
balancing. A simple movie of RCB in action is
(2/14) Added "stable" versions of LAMMPS
to the download page, which undergo more testing than
the incremental versions. Hopefully this makes it easier for users to
upgrade their version only periodically.
(1/14) Added an idea due to John Grime (U
Chicago), to define templates of molecular topology info for systems
with many small molecules, to avoid the memory cost of duplicating the
information. See the atom_style template
command for details.
(1/14) Added MPI-IO support for
reading/writing restart and
dump files in parallel.
(1/14) Added support for 64-bit atom IDs,
so that molecular systems with up to 2^63 = ~9e19 atoms can be
modeled. See Section 2.4 of the
manual for how to enable this option at build time.
(see the Pictures and
Movies pages for more examples of LAMMPS
This is work by Shengfeng Cheng (chengsf at vt.edu) at Virginia Tech
and Gary Grest at Sandia, to model self-assembly of nanoparticles at a
liquid-vapor interface, induced by evaporation of the surrounding
solvent. The quality of the remaining nanoparticle crystal structure
is a result of the competition between evaporation rate and
nanoparticle diffusion time.
The first figure shows snapshots of the simulation from different
views. The second is a Voronoi tesselation of the top layer of the
nanoparticle substrate. The coloring in both figures is based on a
hexagonal order parameter for the local neighborhood of each
particle. The third figure is an animation of the evaporation and
This paper has further details:
Molecular dynamics simulations of evaporation-induced nanoparticle
assembly, S. Cheng and G. S. Grest, J Chem Phys, 138, 064701 (2013).