Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is a molecular dynamics program from Sandia National Laboratories.

[1] LAMMPS makes use of Message Passing Interface (MPI) for parallel communication and is free and open-source software, distributed under the terms of the GNU General Public License.

[2] On parallel computers, LAMMPS uses spatial-decomposition techniques to partition the simulation domain into small 3D sub-domains, one of which is assigned to each processor.

LAMMPS is most efficient (in a parallel computing sense) for systems whose particles fill a 3D rectangular box with approximately uniform density.

Lots of accelerators are supported by LAMMPS, including GPU (CUDA, OpenCL, HIP, SYCL), Intel Xeon Phi, and OpenMP, due to its integration with Trilinos.