LAMMPS Molecular Dynamics Simulator
lamp: a device that generates light, heat, or therapeutic radiation;
something that illumines the mind or soul. -- www.dictionary.com
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 21 May 2008.
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. This includes links to the last major release,
the latest upgraded version with all subsequent bug fixes and new
features, and 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 here along with other contributors. Funding for
LAMMPS development has come primarily from DOE (OASCR, OBER, ASCI,
LDRD, Genomes-to-Life) and is acknowledged here.
Recent LAMMPS News
(7/08) Addition of particle-based
Peridynamics continuum model with new atom_style
and force field.
(5/08) Posted some benchmark
numbers for LAMMPS running on a Dell desktop box with dual
quad-core Intel Xeon chips.
(5/08) Release of 21 May 2008 version of
LAMMPS. New features include a revamping of how temperatures are
computed with bias velocities subtracted and how they work with
various thermostats, and a more robust line-search and stopping
criteria in energy minimization. New commands
added are angle_style cosine/delta,
compute group/group, compute
reduce, fix
temp/berendsen, fix
press/berendsen, fix
nve/sphere, fix
nvt/sphere, fix
npt/sphere, compute
temp/com, compute
temp/sphere, compute
erotate/sphere, compute
erotate/asphere, fix
thermal/conductivity, pair_style
lj/gromacs, pair_style
lj/gromacs/coul/gromacs, and fix
bond/swap. The delete_atoms
overlap command was enhanced. Two new tools
were added: a lmp2vmd tool for
post-processing to VMD format and a directory of Python
post-processing scripts. Two USER
packages were also added: a USER-CG-CMM package for coarse-grained
models and a USER-SMD package for steered MD. See details
here.
(1/08) Release of 22 Jan 2008 version of
LAMMPS. New features include revamped LAMMPS output
options for thermodynamic and dump
output, thermo_style custom and dump
custom can now access computes, fixes, and variables
directly, new enhanced versions of the fix
ave/time, fix
ave/spatial, and fix
ave/atom commands, per-atom energy and virial
tabulations for all pair and many-body potentials and fixes that
invoke internal constraints, and a new easier-to-use variable
formula syntax. New commands added are fix
dt/reset, pair_style
lubricate, pair
coul/debye, fix
coord/original, compute
pe/atom, compute
stress/atom, compute
sum, pair_style
resquared, fix
viscosity, and compute
displace/atom. Deprecated commands
are "fix gran/diag", "compute epair/atom", "compute ebond/atom",
"compute variable/atom", "compute variable", "compute sum/atom", and
"compute attribute/atom". See details here.
(10/07) Release of 5 Oct 2007 version of
LAMMPS. New features include displace_box,
change_box, compute
ebond/atom, changes to 2d pressure
computation, rigid bodies with fix
deform, pair_style airebo,
fix nve/limit, fix
ave/atom, compute
attribute/atom, compute
sum/atom, user-contributed
packages, pair_style
hybrid/overlay for superposing pairwise
potentials, kspace_style ewald/n for
long-range dispersion contributions from 1/r^6 LJ terms, pair_style
lj/coul, pair_style
buck/coul, compute
ackland/atom. See details
here.
(6/07) Release of 22 Jun 2007 version of
LAMMPS. New features include static and
dynamic non-orthogonal simulation boxes
(triclinic symmetry), fix heat, if
command, new Finnis/Sinclair EAM potentials,
displace_atoms random, new
set options, create_atoms
single, compute
coord/atom, fix
ave/time, fix
ave/spatial, variable
atom, new COLLOID package with pair
colloid potential and
neighbor and communication
options to support it, new DIPOLE package for point-dipole particles
with pair dipole/cut, new ASPHERE package for
ellipsoidal particles with a GayBerne
potential and aspherical particle
integrators to support it, NEMD simulations
via fix deform and fix
nvt/sllod and compute
temp/deform, and
tools/pymol_asphere for ellipsoidal
particles. See details here.
- Old
LAMMPS Highlight
(see the Pictures and
Movies pages for more examples of LAMMPS
calculations)
This is work by Seung Soon Jang (jsshys at wag.caltech.edu) in
Bill Goddard's group at Cal Tech.
The 1st picture/paper are for a model they've developed of a
dendrion diblock copolymer consisting of a dendritic polymer with a
hydrophobic backbone. Such materials have interesting nanoscale
structural and phase behavior.
The 2nd picture/paper are for simulations of amphiphilic bistable
(2)rotaxane molecules which have controllable switching properties as
their conformation changes.
The 3rd picture/paper are studies of the structure and surface
concentrations of different surfactants in thin Newton black films.
The 1st picture shows the molecular structures of a diblock copolymer
system at two different levels of water content. The 2nd picture
illustrates conformational changes in a Langmuir monolayer of the
rotaxane molecules. The 3rd picture shows film structure at varying
surface concentrations (top) and film thicknesses (bottom).
These papers have further details:
Nanophase-segregation and water dynamics in the dendrion diblock
copolymer formed from polyaryl ethereal dendrimer and linear PTFE,
S. S. Jang, S.-T. Lin, T. Cagin, V. Molinero and W. A. Goddard
III, J Phys Chem B, 109, 10154-10167
(2005). (abstract)
Molecular dynamics simulation of amphiphilic bistable (2)rotaxane
Langmuir monolayer at air/water interface, S. S. Jang,
Y. H. Jang, Y.-H. Kim, W. A. Goddard III, J. W. Choi, J. R. Heath,
A. H. Flood, B. W. Laursen, and J. F. Stoddart, J Amer Chem Soc, 127,
14804 (2005). (abstract)
Structures and Properties of Newton Black Films Characterized Using
Molecular Dynamics Simulations, S. S. Jang and W. A. Goddard
III, J Phys Chem B, 110, 7992-8001
(2006). (abstract)