Installing open source PyMol on a Mac

This is a quick “how to” post. There is a licensed version of PyMol (MacPyMol) available, but the open source version can be installed on a Mac free of charge. The official page has a guide, which is not terribly detailed, and I found this excellent guide which is unfortunately out-of-date.

Here is an updated guide to installing PyMol using Homebrew on macOS Mojave 10.14.3

Step 1 is to install Homebrew

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Next step is to install the PyMol dependencies using Homebrew

brew install Caskroom/cask/xquartz
brew install tcl-tk
brew install python

Now install PyMol.

brew install brewsci/bio/pymol

You can now run PyMol by typing

pymol

The MPIBR-Bioinformatics page has the following guide to make a little executable app to launch PyMol straight from the Desktop.

• Open Automator, which is in Applications in macOS.
• Create new document, select “Application”.
• Select “Actions” and “Library” in the left pane. Select “Utilities” and “Run Shell Script”. Drag this into the main pane.
• Choose “/bin/bash” as a shell.
• Paste the following: /usr/local/bin/pymol -M. If this doesn’t work, check the path to pymol using which pymol in the terminal, and use this instead.
• Save the application (“File > Save”) to the Desktop and name it “PyMol”.

Now you can double-click this app to run PyMol.