Version 5 (modified by toby, 11 years ago) (diff)


Installing GSAS-II on Mac OS X

Prerequisites: Before GSAS-II can be used on your computer, you must have python installed with a number of required Python packages (see below.) Further, we recommend using another software package, subversion, to download GSAS-II, but that is already present on most Macs.

If you can help expand any of these instructions, discover new mechanisms for installing Python, or have problems getting this to work, please let me know.


Python is a computer scripting language, which means that one must have the Python interpreter installed on your Mac to run a Python program. Macs come with python installed, but not with all the 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 on Macs.

We use the Enthought Python Distribution (EPD) package for our code development (Argonne has a site license). There is also a free version of this package, called EPDFree that will run GSAS-II with addition of one small package (see below). Note that the versions of python supplied with OS X so far are pretty old, so adding the missing packages is probably not a good idea. Use of the Fink or DarwinPorts versions of Python is also not the best choice -- the GUI and graphics will be shown in X-windows; if this indeed does work, the performance will be poor. Note that at this time, GSAS-II does not support Python 3.0 or greater and Python 2.7 is recommended.

GSAS-II has only been run on Intel (i386) Macs running 10.5 (Leopard) and 10.6 (Snow Leopard). We expect no problems with 10.7 (Lion) or 10.8 (Mountain Lion). Getting GSAS-II to run on 10.4 or PPC Macs may be possible, but will likely require considerable work to build/install python packages and compilers and is not recommended except to the cognoscenti.

  • Enthought Python Distribution (EPD) is a commercially licensed Python package that features differing levels of support. It appears that academic users can obtain this for free at this link It is usually distributed as an ~250Mb .dmg file that requires admin privs for installation (but note that at a version that can be installed without admin privs is here: Installation from the .dmg is easy: click on the file to open it (that might happen automatically when you download it). In that new volume, 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. It works best to run this from the account where you will run GSAS-II and supply the name of the admin account when requested, as this will cause your login shell setup file to be updated so that directory /Library/Frameworks/Python.framework/Versions/Current/bin is in your path. (This is done by adding lines like this to file ~/.profile:
    # Setting PATH for EPD-7.2-2
    export PATH
  • We have done some testing with the freely distributed EPDFree package. This is a ~72Mb .dmg file that also requires admin privs to install. Follow the previous installation directions. EPDFree provides everything one needs to run GSAS-II except the interface needed for OpenGL graphics (PyOpenGL) which can be added. GSAS-II will attempt to install this package for you.
  • ActiveState ActivePython This is also commercial licensed software. There is a free version with no support. We have not tried this yet.


Subversion is a software version tracking system that allows you to download and update the GSAS-II software from the APS subversion server ( Macs with 10.5 (Leopard) and 10.6 (Snow Leopard) have this. As mentioned, while GSAS-II can probably be run on 10.4, this is probably a lot more work than one would like.

Compiling Fortran Code

You can probably skip this step: GSAS-II requires a small number of Fortran routines that are incorporated as Python packages (.so files). GSAS-II is distributed with these files compiled for Python 2.7 and Mac OS X 10.5 and 10.6+, but if you are using something that does not match this, you may need to compile the Fortran routines yourself using the NumPy f2py routine and the compiler of your choice. Both G77 and GFortran have worked on the Mac.

To help with compiling the programs, use the python scons routine inside the GSASII/fsource directory. If you are lucky, this routine will find the needed compiler and python program, set all options correctly for you and run all steps needed to prepare the .so files. This is done by

(1) opening a Terminal or xterm window,

(2) using the cd command to set your working directory to .../GSASII/fsource and

(3) simply typing "scons" in the window.

If you need to change any options, type "scons help" to see a list of the possible command-line arguments and the values for the options. For testing, help can be used with command-line options to see how they will change the variables.


We prefer that GSAS-II be installed using subversion so that it is easy to get updates (which are frequent). Fortunately, since 10.5, Macs come with subversion installed. This procedure loads GSAS-II using subversion:

  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.

Note that GSAS-II can be updated by use of the, which will download any newly created or updated program files.

Errors from

The error messages from the are placed in a file named GSASIIerrors in the user's home directory

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