Dear LAMMPS Users and Developers,
I am pleased to announce a new LAMMPS feature release (version 4 July 2026) that was just made available for download on GitHub and on the LAMMPS homepage.
You can see the detailed release notes here: Release Feature release 4 July 2026 · lammps/lammps · GitHub
The binary packages with the LAMMPS and the GUI now include LAMMPS-GUI version 3.0.1 which was released at the same time. LAMMPS-GUI 3.0.x is a major upgrade over the version 1.x series and has seen a major internal refactor.
Standalone versions of the LAMMPS-GUI binaries are also available. Those now include a LAMMPS 4 July 2026 shared library. Since the LAMMPS library is loaded dynamically in these packages, it can be switched to a different version (e.g. a customized version) though the preferences, but at least version 4 July 2026 is required since it depends on feature not available in older LAMMPS versions. The most visible changes in LAMMPS-GUI are new library of vector graphics icons and a new custom plot widget. The release notes are here: Release Version 3.0.1 · akohlmey/lammps-gui · GitHub
Given the occasion of the 250th anniversary of the United States of America, this is a very big release (about 5x the amount of changes than what is typical for LAMMPS) with many new features and bugfixes. A few highlights:
- ports of many styles to the KOKKOS and OPENMP packages
- a new constraint solver fix ilves that can handle clusters of connected bonds (unlike fix shake), this was adapted from a GROMACS version with the assistance of the researchers that developed the ILVES family of constraint algorithms
- The option to model surface of arbitrary shape represented by triangle meshes read from an STL file with the new GRANSURF package
- the option to also color bonds by property and not only atoms in dump image
- extended testing support: it is now possible to run tests on the GPU also with KOKKOS and test KOKKOS with single, mixed or double precision.
- extended testing and validation for the GRANULAR package in the unittest tree
- import and export of default color and lighting settings with JSON files
- new packages LDD, ML-RUNNER
- resolving many feature requests and bug reports in the issue tracker
As a special gimmick to go along with the extended testing we now have a LAMMPS Testing Dashboard Website where you can see the consolidated test status across the entire test matrix and links to the individial issues.