Version 1 (modified by toby, 12 years ago) (diff)


Installing GSAS-II on Mac OS X

Prerequisites: Before GSAS-II can be used on your computer, you must have two software packages installed, python and subversion. With 10.5 and 10.6, OS X comes with both installed, but alas, the supplied python versions do not include all the required packages (see below). Note that at present GSAS-II is only distributed via subversion. If you work at an institution with a firewall that blocks downloading files from subversion (uncommon, but known), contact your computer support department or arrange to perform the download from another location.


Python is a computer scripting language, which means that one must have the Python interpreter installed on your Mac to run a Python program. However, there are a number of Python packages required by GSAS-II that are not distributed within Python so some software installation is required. Note the required WxPython package runs only in 32-bit python.

There are at least two options for loading a complete Python implementation. The EPD package is what we use for code development. In theory, you might be able to load just the missing packages, but it is not clear how easy that is to do. Use of the Fink or DarwinPorts versions of Python is probably not a good idea -- the GUI and graphics will be shown in X-windows; if this indeed works, the performance will be poor. Feedback on packages other than EPD is welcome. Note that at this time, GSAS-II does not support Python 3.0 or greater and Python 2.7 is recommended.

  • Enthought Python Distribution (EPD) is commercial licensed software that is distributed at no cost to students and employees of academic organizations. To install, download the .dmg file and click on it (if needed) to mount it. You will see the EPD.mpkg installer. Click on that to start the installation process. Note that admin privileges are required to load this package.


Subversion is a software version tracking system that allows you to download and update the GSAS-II software from the APS subversion server ( It is already installed in 10.5 (Leopard) and 10.6 (Snow Leopard) but not 10.4 Subversion likely can be found and downloaded for 10.4, but the latest EPD releases require 10.5 or later. GSAS-II can probably be made to run on 10.4, but this is not recommended.


  1. Create a folder where you want to install GSAS-II.
  1. Download file file using this link:

or use this command:

curl >

  1. Move that file into the new GSAS-II folder
  1. Run the file by double-clicking on it or using the command "python"
  1. This creates a file that can be used to start GSAS-II either by clicking on the app or by dragging a file onto the app. Note that the app file can be dragged to the doc, but it cannot be moved to another folder. Instead, create an alias and move the alias where desired.

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