LAMMPS version 29 Oct 2020 Documentation

LAMMPS stands for Large-scale Atomic/Molecular Massively Parallel Simulator.

LAMMPS is a classical molecular dynamics simulation code with a focus on materials modeling. It was designed to run efficiently on parallel computers. It was developed originally at Sandia National Laboratories, a US Department of Energy facility. The majority of funding for LAMMPS has come from the US Department of Energy (DOE). LAMMPS is an open-source code, distributed freely under the terms of the GNU Public License (GPL).

The LAMMPS website has a variety of information about the code. It includes links to an on-line version of this manual, a mailing list where users can post questions, and a GitHub site where all LAMMPS development is coordinated.


The content for this manual is part of the LAMMPS distribution. The online version always corresponds to the latest development version. If needed, you can download or build a local copy of the manual as HTML pages or a PDF file by following the steps on the Build the LAMMPS documentation page. If you have difficulties viewing the pages please see this note.


The manual is organized in two parts: 1) the User Guide for how to install and use LAMMPS and 2) the Programmer Guide for how to write programs using the LAMMPS library from different programming languages and how to modify and extend LAMMPS.

Once you are familiar with LAMMPS, you may want to bookmark this page since it gives quick access the documentation for all LAMMPS commands.


User Guide

User Guide

Indices and tables

Web Browser Compatibility

The HTML version of the manual makes use of advanced features present int “modern” web browsers. This can lead to incompatibilities with older web browsers (released more than 4 years ago) and specific vendor browsers (e.g. Internet Explorer on Windows; Microsoft Edge works well though) where parts of the pages are not rendered as expected (e.g. the layout is broken or mathematical expressions not typeset). In that case we recommend to install/use a different/newer web browser or use the PDF version of the manual.