LAMMPS Tutorial Preparations

Asking for help
If you get stuck somewhere during the self-study parts of the tutorial, please reach out to us by raising your hand or writing a message on the dedicated LAMMPS Workshop Slack.

If you are not yet a member of the LAMMPS Workshop Slack, there will be a link posted here about a month in advance of the workshop where you can join.

Please note that this Slack will only be monitored by LAMMPS developers in the time before and during the workshop. If you need to ask for assistance with LAMMPS outside of that time, you can post your questions in the LAMMPS forum on MatSci.org. Please make sure you have read, understood, and follow the forum guidelines to increase your chance to get comprehensive help quickly.

Preparation

To avoid spending time on compilation and installation software, the tutorial session is desiged around the LAMMPS-GUI and OVITO applications for which pre-compiled packages for Linux, macOS, and Windows are available for download.

Install the LAMMPS-GUI package for your platform

Download for Windows
Download for macOS
Download tarball for Linux
Download flatpak for Linux

LAMMPS-Win10-64bit-GUI-develop.exe
SHA256: 496f2bf27c1cbea209e31fcc7c7804a2980dc9e28b22fbee8ce229166e425ee8
LAMMPS-macOS-multiarch-GUI-develop.dmg
SHA256: 84936102d21a6e935896e1ff2b2715cedaca219014c173b7f28ef65eeeae5668
LAMMPS-Linux-x86_64-GUI-develop.tar.gz
SHA256: a847481a877dfdcb00594fd17f9729e809e592263bdca813ae040925716ae13f
LAMMPS-Linux-x86_64-GUI-develop.flatpak
SHA256: c3dd8afa69e66dd8d9d83688085d3a0416e0e9a16daad2103909740724e417ff

Windows

Download the Windows installer package and find it in your Downloads folder. Depending on your security settings, you may have to explicitly tell Windows to download the file and to keep the downloaded file despite its claims that it may be dangerous and insecure.

Execute the Windows installer package and - if desired - customize the installation location. The installer contains LAMMPS-GUI, the command-line LAMMPS executable (lmp), several related tools, potential files, and example inputs from the source code

macOS

Download the macOS DMG file and open it. The mounted disk image will have a graphical installer, which instructs you to drag the LAMMPS app into your Applications folder. Doing so will require admin rights.

Follow the steps in the README.txt file to enable access to the command-line executables in addition to LAMMPS-GUI.

Linux tarball

Download the Linux tarball and find it in your Downloads folder. Extract the tarball either via Right-Click -> Extract, or use a terminal with the tar command:


    cd ~/Downloads
    tar -xzvvf LAMMPS-Linux-x86_64-GUI-develop.tar.gz

The Linux package contains a LAMMPS_GUI folder with the various commands. If desired, you can move this folder to a more suitable, permanent location and update your PATH environment variable to search this folder for commands.

Linux flatpak

Download the Linux flatpak bundle and find it in your Downloads folder. To install applications from flatpak bundles, you first need to install the flatpak environment into your Linux system. From a terminal window you can install the bundle into your account with the command:


    cd ~/Downloads
    flatpak install --user LAMMPS-Linux-x86_64-GUI-develop.flatpak

The flatpak bundle should integrate the application into your desktop environment and LAMMPS-GUI should be listed under "Applications -> Science". It is also possible to launch it from a terminal window with:


    flatpak run org.lammps.lammps-gui

The LAMMPS command-line version, lmp (and other bundled command-line executables) can be launched the following way:


    flatpak run --command=lmp org.lammps.lammps-gui

Other included command-line tools can be listed with:


    ls $(flatpak info --show-location org.lammps.lammps-gui )/files/bin

Install the OVITO application for your platform

Go to the OVITO download page and download the version suitable for your platform. Then follow the installation instructions for your platform from the OVITO documentation.

Known issues

Configuring `https_proxy` in LAMMPS-GUI for downloading tutorial files

LAMMPS-GUI includes functionality to automatically download any files necessary for the individual tutorials. If you are required to use a web proxy (for security reasons or otherwise) this can be configured in the “Preferences” dialog of LAMMPS-GUI.

macOS: LAMMPS-GUI.app is damaged and can’t be opened. You should move it to the Trash

Verify that the download was not corrupted

shasum -a 256 ~/Downloads/lammps-stable-macos-universal.dmg
# string should match the SHA256 at the top of this page

Open Terminal and run the following command:

Warning
Only proceed if the file was not corrupted during download. The following command disables protections that would normally keep your computer safe from malicious code. If the checksum does not match, redownload the file until it matches.
```
# this will clear security attributes in the installed App
# including remove the "this App was downloaded from the Internet" notice
sudo xattr -cr /Applications/LAMMPS-GUI.app/
```