2.5. Download source and documentation as a tarball
You have two choices of tarballs, either the most recent stable release or the most current patch release. Stable releases occur a few times per year, and undergo more testing before release. Patch releases occur a couple times per month. The new contents in all releases are listed on the bug and feature page of the website.
Both tarballs include LAMMPS documentation (HTML and PDF files) corresponding to that version. The download page also has an option to download the current-version LAMMPS documentation by itself.
Older versions of LAMMPS can also be downloaded from this page.
Once you have a tarball, unzip and untar it with the following command:
$ tar -xzvf lammps*.tar.gz
This will create a LAMMPS directory with the version date in its name, e.g. lammps-23Jun18.
You can also download a zip file via the “Clone or download” button on the LAMMPS GitHub site. The file name will be lammps-master.zip which can be unzipped with the following command, to create a lammps-master dir:
$ unzip lammps*.zip
This version is the most up-to-date LAMMPS development version. It will have the date of the most recent patch release (see the file src/version.h). But it will also include any new bug-fixes or features added since the last patch release. They will be included in the next patch release tarball.
If you download a current LAMMPS tarball, one way to stay current as new patch tarballs are released, is to download a patch file which you can apply to your local directory to update it for each new patch release. (Or of course you could just download the newest tarball periodically.)
The patch files are posted on the bug and feature page of the website, along with a list of changed files and details about what is in the new patch release. Instructions for applying a patch file are on the Install patch doc page.