# LAMMPS Documentation ( version)

LAMMPS stands for **L**arge-scale **A**tomic/\*\*M\*\*olecular
**M**assively **P**arallel **S**imulator.

LAMMPS is a classical molecular dynamics simulation code focusing on
materials modeling. It was designed to run efficiently on parallel
computers and to be easy to extend and modify. Originally developed at
Sandia National Laboratories, a US Department of Energy facility, LAMMPS
now includes contributions from many research groups and individuals
from many institutions. Most of the funding for LAMMPS has come from the
US Department of Energy (DOE). LAMMPS is open-source software
distributed under the terms of the GNU Public License Version 2 (GPLv2).

The [LAMMPS website](https://www.lammps.org)\_ has a variety of
information about the code. It includes links to an online version of
this manual, an [online forum](https://www.lammps.org/forum.html)\_
where users can post questions and discuss LAMMPS, and a [GitHub
site](https://github.com/lammps/lammps)\_ where all LAMMPS development
is coordinated.

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The content for this manual is part of the LAMMPS distribution. The
online version always corresponds to the latest feature release version.
If needed, you can build a local copy of the manual as HTML pages or a
PDF file by following the steps on the [Build_manual]{.title-ref} page.
If you have difficulties viewing the pages, please [see this
note](webbrowser).

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The manual is organized into three parts:

1.  The [User Guide](user_documentation) with information about how to
    obtain, configure, compile, install, and use LAMMPS,
2.  the [Programmer Guide](programmer_documentation) with information
    about how to use the LAMMPS library interface from different
    programming languages, how to modify and extend LAMMPS, the program
    design, internal programming interfaces, and code design
    conventions,
3.  the [Command Reference](command_reference) with detailed
    descriptions of all input script commands available in LAMMPS.

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::: only
html

After becoming familiar with LAMMPS, consider bookmarking [this
page](Commands_all), since it gives quick access to tables with links to
the documentation for all LAMMPS commands.
:::

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## User Guide {#user_documentation}

::: {#userdoc .toctree maxdepth="2" numbered="3" caption="User Guide" includehidden=""}
Intro Install Build Run_head Commands Packages Speed Howto Examples
Tools Errors
:::

## Programmer Guide {#programmer_documentation}

::: {#progdoc .toctree maxdepth="2" numbered="3" caption="Programmer Guide" includehidden=""}
Library Python_head Modify Developer
:::

## Command Reference

> commands_list fixes computes pairs bonds angles dihedrals impropers
> dumps fix_modify_atc_commands Bibliography

## Indices and tables

::: only
html

-   [genindex]{.title-ref}
-   [search]{.title-ref}

The HTML version of the manual makes use of advanced features present in
\"modern\" web browsers. This leads to incompatibilities with older web
browsers and specific vendor browsers (e.g. Internet Explorer on
Windows) 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](https://docs.lammps.org/Manual.pdf)\_.

The following web browser versions have been verified to work as
expected on Linux, macOS, and Windows where available:

-   Safari version 11.1 and later
-   Firefox version 54 and later
-   Chrome version 54 and later
-   Opera version 41 and later
-   Edge version 80 and later

Also Android version 7.1 and later and iOS version 11 and later have
been verified to render this website as expected.
:::