This page is a continuous listing of new features and bug fixes for the LAMMPS molecular dynamics package. It also lists periodic "stable" versions which have undergone more testing.
See the unfixed bug page for info on how to report bugs or issues you find wtih LAMMPS.
In some cases, new features change the syntax or operation of an existing input script command, which can cause LAMMPS output to change, or even "break" an earlier working script. These cases are highlighted below with a "BACKWARD COMPATIBILITY" note.
To stay up-to-date with the current LAMMPS, you have two choices:
This page contains a year's worth of new features and bug fixes.
Past years of features/fixes are here: 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004
Periodic summaries of major new features added to LAMMPS are on the history page.
A LAMMPS "version" is the date when it was released, such as 1 Oct 2020. LAMMPS is updated continuously. Each time we fix a bug or add a feature, we make it immediately available in the LAMMPS git repository hosted on GitHub in the "develop" branch. Every 4-6 weeks we publish a feature release, as listed below. Each dated feature release of LAMMPS contains all the new features and bug-fixes in the develop branch up to and including the version date. The version date of the code you are running is printed to the screen and logfile every time you run LAMMPS. It is also on the first page of the HTML version or PDF version of the manual you are reading. It is also in the file src/version.h and in the LAMMPS directory name created when you unpack a tarball.
These are past "stable" versions of LAMMPS, which have successfully passed a suite of build and run tests. This is more testing than is done for the incremental development feature releases listed below.
If you don't want to track the bleeding edge of LAMMPS development, you can download a tarball of the most recent stable version on the download page or from GitHub. A summary of what is in each stable release is provided on the LAMMPS GitHub site.
Earlier stable versions are also available as tarballs on the LAMMPS web site, at this link, using the appropriate date from the list above.
You can use Git to check out a specific stable version in one of two ways, using the tag listed above:
(1) If you do not have an existing checkout:
git clone -b stable_4Nov2016 https://github.com/lammps/lammps.git mylammps
(2) If you already have an existing checkout:
git fetch origin git checkout -b release-4Nov16 stable_4Nov2016
which will create a branch with the name "release-4Nov16", with all the files for that specific stable release.
Likewise, you can use SVN to check out a specific stable version, using the tag listed above:
svn checkout https://github.com/lammps/lammps.git/tags/stable_4Nov2016 mylammps
Additional info on how to track other branches (stable, maintenance, release, develop) of the GitHub LAMMPS repository via Git or SVN are linked to on the download page.
21 Nov 2023
Details on what changed in this feature release are here and details for all past releases are here.
Only new features or notable changes are highlighted here:
New compute composition/atom command to calculate local atom type compositions (Megan McCarthy, SNL) PR #3871
New fix press/langevin command for a langevin based barostat (Germain Clavier, TU Eindhoven) PR #3791
New pair style nb3b/screened which computes a screened angle interactions compared to nb3b/harmonic (Federica Lodesani, University of Modena) PR #3960
New snap/intel pair style implementing AVX512 vectorization for use with Intel compiler and x86 CPUs (Mike Brown, Intel) PR #3921
Add support for numerical integrators without normal mode transformation to fix pimd/langevin (mode pimd). (Yifan Li, Princeton University) PR #3970
New KOKKOS versions of fix efield, fix spring/self, and pair style yukawa/colloid (Trung Nguyen, U Chicago) PR #3909
Add option to do anti-aliasing for better image quality with dump image and dump movie (Axel Kohlmeyer, Temple U), PR #3889
Refactoring of handing of references to computes and fixes to consistently index global and per-atom properties. (Steve Plimpton) PR #3896
BACKWARD COMPATIBILITY:
The MSCG package and thus fix mscg has been removed
The MPIIO package has been removed. The corresponding dump styles are no longer available and .mpiio restarts cannot be read anymore
CMake version 3.16 or later is now required to build LAMMPS with CMake
A C++17 capable compiler is now required to compile the KOKKOS package
Using a triclinic simulation cell now requires atom IDs due to changes in the neighbor list build algorithms
The refactoring of variable access to compute and fix data has the following consequences:
(1) the compute voronoi/atom peratom option was dropped; it now always produces peratom data. The local option is now used to also generate local data
(2) an inputs option was added to compute reduce to operation on peratom (default) or local data. You must use it to operate on local data
(3) the rules for equal, vector, atom-style variables changed a bit for how they access output from computes and fixes. An equal-style variable can access any kind of data, using C_ID, instead of c_ID (similar for fixes) to access per-atom data instead of global data.
(4) vector and atom-style varaiables can only access global vector and per-atom data directly. They can use an equal-style variable to access other kinds of data indirectly.
2 Aug 2023
This is a stable release.
Details on what has changed in this release (compared to the previous stable release) are here and details for all releases are here.
15 Jun 2023
Details on what changed in this feature release are here and details for all past releases are here.
Only new features or notable changes are highlighted here:
The LATTE package was removed as it is superseded by the MDI package which provides a more generic interface to couple to quantum codes (Steve Plimpton) PR #3716
Updates to fix mdi/qm and fix mdi/qmmm to be compatible with quantum codes that do not support periodic boundaries (Taylor Barnes, MolSSI) PR #3727
Update COLVARS package to version 2023-05-01 (Giacomo Fiorin, NIH and Colvars developers) PR #3783
Update bundled Kokkos library to version 3.7.2 (Stan Moore, SNL, and the Kokkos developers) PR #3806
Add support for exchange communication for fixes to KOKKOS, this can provide significant speedups for certain simulations using GPUs (Stan Moore, SNL, based on work by Denis Taniguchi, Newcastle University) PR #1394
Multiple performance optimization for KOKKOS package with GPUs (Stan Moore, SNL): (1) Add support for performing the spatial sorting of atoms on GPU devices, PR #3740 (2) Fuse some Kokkos kernels to reduce launch latency for small systems, PR #3758 (3) Compute atom map (including hash style) on GPU devices, PR #3769
New pair styles lj/cut/sphere, lj/expand/sphere, and lepton/sphere which use the individual particle diameter from atom style sphere as a potential property instead of a per-type pair_coeff setting (Axel Kohlmeyer, Temple U) PR #3714
New pair style aip/water/2dm for interfaces between water and 2d materials (Wengen Ouyang, Wuhan University), optimized versions by (Xiaohui Duan, Shandong University, and Ping Gao ,National Supercomputing Center in Wuxi) PR #3787
New compute count/type command to efficiently count number of atoms or bonds of given types (Steve Plimpton) PR #3761
New fix pimd/langevin for path-integral simulations using a Langevin thermostat (instead of a massive Nose-Hoover) (Yifan Li, Princeton) PR #3660
Add support for setting and outputting vector style variables with a python-list-like format (Steve Plimpton) PR #3767
Add support for fix adapt to pair style kim (global scale factor only) (Ilia Nikiforov, U of Minnesota) PR #3777
Add support for bond and angle style contributions to compute stress/mop and compute stress/mop/profile (Evangelos Voyiatzis, NovaMechanics Ltd) PR #3792
Add support for bond style forces to compute stress/cartesian (Lars Veldscholte, University of Twente) PR #3797
Multiple bugfixes and enhancements for the INTEL package (Mike Brown, Intel) PR #3812
Enhancements for PyLammps (Richard Berger, LANL) PR #3811
BACKWARD COMPATIBILITY:
The LATTE package and fix latte command are no longer available
28 Mar 2023
Details on what changed in this feature release are here and details for all past releases are here.
Only new features or notable changes are highlighted here:
Support more pair, bond, and angle styles with compute born/matrix (Evangelos Voyiatzis) PR #3650, PR #3655, PR #3668
Refactor of the GRANULAR package to make it more modular and features more easily reusable (Joel Clemmer and Dan Bolintineanu, SNL) PR #3512
New fix wall/lepton and wall/table for custom wall potentials (Axel Kohlmeyer, Temple U) PR #3657
New bond style harmonic/restrain to restrain bonds to their current length (Axel Kohlmeyer, Temple U) PR #3671
New fix alchemy and compute pressure/alchemy commands for multi-partition alchemical transformations (Axel Kohlmeyer, Temple U) PR #3662
New fix mdi/qmmm style and examples for coupling LAMMPS to quantum codes (PySCF, NWChem, LATTE) via MDI for QM/MM simulations (Steve Plimpton) PR #3628
GPU package performance improvements (Mike Brown, Intel) PR #3675
New pair style born/gauss which is used as example in new programmer's guide section on developing pair styles (Axel Kohlmeyer, Temple U), PR #3667
Refactor per-chunk compute styles to use a common base class and thus reduce replicated code, (Axel Kohlmeyer, Temple U), PR #3691
8 Feb 2023
Details on what changed in this feature release are here and details for all past releases are here.
Only new features or notable changes are highlighted here:
Port of the AMOEBA package code to the GPU package (Trung Nguyen, U Chicago) PR #3599
Port of pace/extrapolation pair style to KOKKOS (Yury Lysogorskiy (ICAMS, RUB) PR #3585, PR #3629
Port of pair styles lj/expand/coul/long and lj/cut/dipole/cut and atom style dipole to KOKKOS (Trung Nguyen, U Chicago) PR #3623
Port of the ML-IAP Python interface for PyTorch to KOKKOS (Matt Bettencourt, NVIDIA) PR #3577, PR #3606
New pair style meam/ms implementing the multi-state MEAM extension including port to KOKKOS (Drew Rohskopf and Aidan Thompson, SNL, and Mike Baskes, LANL, UNT) PR #3608
Remove mesont/tpm pair style and related styles as well as the corresponding Fortran library from MESONT package as they are superseded by the mesocnt pair and bond/angle styles. (Axel Kohlmeyer, Temple U) PR #3605
New LEPTON package that allows custom potential functions through evaluating expressions provided as string through the Lepton library written originally for OpenMM (Axel Kohlmeyer, Temple U) PR #3571, PR #3590
New angle_write and dihedral_write commands (Axel Kohlmeyer, Temple U) PR #3573
New compute efield/wolf/atom command that can approximate the electrostatic field at atom positions using Wolf summation (Axel Kohlmeyer, Temple U) PR #3551
Bugfix for DPD-BASIC pair styles and their accelerated versions when used with bonds and special_bonds factors that are not 0 or 1. (Axel Kohlmeyer, Temple U) PR #3575
Updates to the DIELECTRIC package that reverses the logic of how to store original and scaled charges and thus results in more consistent behavior of computes and fixes outside the DIELECTRIC package (Trung Nguyen, UChicago) PR #3576
Support for ABC-FIRE variant of FIRE minimizer (Sebastian Echeverri Restrepo, King's College London) PR #3591, PR #3594
Support for "equal" mode of NEB (Tom D Swinburne, CNRS), PR #3596