Latest Features and Bug Fixes in LAMMPS

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:

Download the current feature tarball or most recent stable tarball from the download page. The same tarballs are also available for download on the LAMMPS GitHub releases page

• The feature version includes all the features/fixes listed below. The stable version has undergone more build and run testing and is issued periodically (every few months). Once you download the tarball, you must re-build LAMMPS from scratch. Downloads of executable files for various platforms are also available on the download page.
• Use the LAMMPS GitHub site to create an initial git clone or fork of LAMMPS. You can then pull incremental updates thereafter. Each stable and feature release are tagged individually. The repository has four permanent branches: "develop", "release", "maintenance", and "stable". The "develop" branch is the active development branch, the "release" branch is updated from "develop" with each feature release. The "maintenance" branch contains backports of bugfixes and infrastructure changes from "develop" for the latest stable release. The "stable" branch follows the stable releases and is updated from either "maintenance" (update releases) or from "release" (stable releases). Instructions on using Git are linked to on the download page.

This page contains a year's worth of new features and bug fixes.

Past years of features/fixes are here: 2025 2024 2023 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.

What version of LAMMPS do you have?

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.

• If you browse the HTML doc pages or manual PDF on the LAMMPS website, they describe the current feature release of LAMMPS. HTML doc pages for the current develop branch or last stable release are also available by clicking Version at the lower left of the Manual page (click latest or stable).
• If you browse the HTML doc pages or manual PDF included in a tarball they describe the version the tarball includes.

Stable versions

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.

• 22 Jul 2025 = stable version, tag = stable_22Jul2025_update3
• 29 Aug 2024 = stable version, tag = stable_29Aug2024_update4
• 2 Aug 2023 = stable version, tag = stable_2Aug2023_update4
• 23 Jun 2022 = stable version, tag = stable_23Jun2022_update4
• 29 Sep 2021 = stable version, tag = stable_29Sep2021_update3
• 29 Oct 2020 = stable version, tag = stable_29Oct2020
• 3 Mar 2020 = stable version, tag = stable_3Mar2020
• 7 Aug 2019 = stable version, tag = stable_7Aug2019
• 5 Jun 2019 = stable version, tag = stable_5Jun2019
• 12 Dec 2018 = stable version, tag = stable_12Dec2018
• 22 Aug 2018 = stable version, tag = stable_22Aug2018
• 16 Mar 2018 = stable version, tag = stable_16Mar2018
• 11 Aug 2017 = stable version, tag = stable_11Aug2017
• 31 Mar 2017 = stable version, tag = stable_31Mar2017
• 17 Nov 2016 = stable version, tag = stable_17Nov2016
• 5 Nov 2016 = stable version, tag = stable_5Nov2016
• 30 Jul 2016 = stable version, tag = r15407
• 14 May 2016 = stable version, tag = r15061
• 16 Feb 2016 = stable version, tag = r14624
• 7 Dec 2015 = stable version, tag = r14304
• 10 Aug 2015 = stable version, tag = r13864
• 15 May 2015 = stable version, tag = r13475
• 10 Feb 2015 = stable version, tag = r13095
• 9 Dec 2014 = stable version, tag = r12824
• 30 Oct 2014 = stable version, tag = r12671
• 5 Sep 2014 = stable version, tag = r12430
• 28 Jun 2014 = stable version, tag = r12164
• 1 Feb 2014 = stable version, tag = r11423

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.

Additional info on how to track other branches (stable, maintenance, release, develop) of the GitHub LAMMPS repository via Git are linked to on the download page.

30 Mar 2026

Details on what has changed in this feature release are here and details for all releases are here.

New features or notable changes since the 11 Feb 2025 stable release are highlighted here:

Add support for calculation of conservative AP potentials to the APIP package (David I mmel, Rolf Drautz, Godehard Sutmann, JSC, Juelich and ICAMS, Bochum) PR #4869

Add support for superellipsoid granular particles (Jacopo Bilotto, EPFL and Jibril B. Coulibaly, Joel Clemmer, SNL) PR #4897

Matrix free option for fix qeq/reaxff and device-resident reverse communication for fixes (Even Weinberg and Balint Joo, NVIDIA) PR #4888

Add ClassII-xe angle and dihedral styles to the CLASS2 package (Josh Kemppainen, Michigan Tech) PR #4904

Add options for volume and area preserving barostats to Nose-Hoover barostats (Germain Clavier, Uni Caen, and Shern Tee, Griffith University) PR #4680

Add KOKKOS version of pair style lj/cubic (Aidan Thompson, SNL) PR #4883

Add KOKKOS version of dihedral style nharmonic (Axel Kohlmeyer, Temple U) PR #4933

Add rounded triangle graphics primitive and apply to multiple cases where triangle meshes are used, e.g. ellipsoids, superellipsoids or isosurfaces for smooth instead of edgy surfaces (Axel Kohlmeyer, Temple U) PR #4925

Add new keywords "within" and "exclude" to the group command for dynamic groups (Axel Kohlmeyer, Temple U) PR #4902

Add option to molecule command to derive angles, dihedrals, and impropers from bonds and infer their types from atom typelabels. Also provide runtime check to labelmap command to check for the required consistency (Aya Salama, Jake Gissinger, Stevens Institute of Technology) PR #4894, PR #4916

Add support to request energy only computations from force styles and apply this to multiple MC package fixes. (Axel Kohlmeyer, Temple U) PR #4914

BACKWARD COMPATIBILITY:

• When compiling with C++20 or later enabled and using a fully C++20 compliant compiler, external code may encounter issues with missing include statement, since #include would implicitly use #include and #include for example. These must be included explicitly in any .cpp file using functions declared in those header files.
• Pair style born/coul/long/cs/gpu does not work reliably with single precision and thus now aborts with an error under these circumstances
• Binary restart files changed in an incompatible way when dihedral styles fourier or nharmonic are used or fix style gcmc

11 Feb 2026

Details on what has changed in this feature release are here and details for all releases are here.

New features or notable changes since the 10 Dec 2025 stable release are highlighted here:

New MBX package which is a wrapper around the MBX library for data driven many-body potentials (Henry Agnew, Francesco Paesani, UCSD, and Chris Knight, ANL) PR #4694 and PR #4871

Add compute hbond/local to compute hydrogen bonds and output the list as local data (Axel Kohlmeyer, Temple U) PR #4867

Significant updates to fix nvt/sllod, fix temp/deform, compute temp/deform and related commands for stable integration of the equations of motion in a way which is reversible and energy-conserving (Stephen Sanderson, University of Queensland) PR #4781

Add smooth termination of Coulomb integrals in the Streitz-Mintmire method (Roman Gröger, Czech Academy of Sciences) PR #4733

Add support for use of fix shake with KOKKOS and minimization (Mitch Murphy) PR #4827

Port minimization style fire to KOKKOS (Mitch Murphy) PR #4851

Add support for ellipsoid atom style in KOKKOS (Lewis Russell, University of Strathclyde and Stan Moore, SNL) PR #4865

Add a geometric integrator for overdamped rotational Brownian motion (Artur Straube, Zuse Institute Berlin) PR #4842

Improved inter-bead communication for fix pimd/langevin (Yifan Li, Princeton) PR #4857

Add support for wildcard atom types in fix bond/react and add an interface to type label handling that allows to infer bonded interaction type labels from the types of the constituent atom types (Jake Gissinger, Stevens IoT) PR #4822 and PR #4879

Significant enhancements to dump image (and dump movie) (Axel Kohlmeyer, Temple U) PR #4812 and others

• added an approximation to transparency (via "screen-door transparency" using a 16x16 Bayer matrix)
• added support for visualizing data from fixes to: fix indent, fix reaxff/bonds, fix smd/wall_surface, fix wall/lj93, fix wall/lj126, fix wall/lj1043, fix wall/colloid, fix wall/gran, fix wall/harmonic, fix wall/harmonic/outside, fix wall/lepton, fix wall/morse, fix wall/reflect, fix wall/reflect/stochastic, and fix wall/table
• added support for highlighting atoms involved in MC processes in fix atom/swap', fix bond/break', fix bond/create, fix bond/create/angle, fix mol/swap, and fix neighbor/swap PR #4874
• added a new fix graphics/objects command to place some graphics objects into the visualization including a progress bar and arrows
• updates to body styles rounded/polygon and rounded/polyhedra to display faces plus code refactor PR #4817
• support for ellipsoid particles through using triangle meshes (same as regions) also PR #4817
• added a new fix graphics/arrows command to display per -atom or pre-chunk arrows PR #4819
• added a new fix graphics/isosurface command to display isosurfaces of per-atom data and output them to STL files PR #4823
• added a new fix graphics/labels command to display images or text inside the visualization PR #4826 and PR #4848
• added a new fix graphics/lines command to display traces of averaged atom positions (aka trajectory lines) PR #4876
• added a new fix graphics/periodic command to display periodic images of atoms and bonds PR #4825
• added support for compute styles providing graphics objects to dump image and apply to new compute hbond/local PR #4867
• added support for highlighting atoms in a reaction with fix bond/react PR #4870
• added a "Advanced Graphics Howto" and visualization for plane regions PR #4820
• added an option to dump image to create a vertical background gradient instead of a plain background PR #4823
• consolidate generation of high-level graphics objects in an ImageObjects namespace and move to a separate file PR #4820

BACKWARD COMPATIBILITY:

• Since the Kokkos library version 5.0.0 and later dropped support for building with GNU make, the KOKKOS package in LAMMPS now also only supports building with CMake. The corresponding traditional GNU make build system files were removed or changed accordingly.
• As of version 5.0.0 Kokkos requires at least C++20
• The dump image and dump movie commands are now part of the new GRAPHICS package and thus the package must be installed to have access to them. It was added to the "basic" (and "most") preset and make yes-basic (and make yes-most), so this will affect few users
• The zcylinder keyword was removed from fix wall/gran since it is obsoleted by fix wall/gran/region which is more flexible.
• The amber2lammps.py, dump2trj99.py, and dump2trj.py scripts have been removed from the distribution. They were unmaintained, obsolete, and require Python 2.
• Since the new kick flag of fix nvt/sllod defaults to yes when using lab-frame velocity, scripts which previously applied the velocity profile manually would need to either stop doing that or set kick no.
• Previous scripts will also generate a warning about fix deform being applied at the end of the step, and suggest setting nevery = 0 in fix deform to correct the issue.
• With fix nvt/sllod now having compute temp/deform as a hard requirement, scripts which used some other velocity bias will need to adapt by setting that bias via the new temp argument of compute temp/deform.