Version 6 (modified by toby, 21 months ago) (diff)


Installing GSAS-II on Windows the Hard Way

Overview: Installing GSAS-II requires three things: installing a Python distribution, a download package (subversion) and the actual GSAS-II code.

Use these instructions if you are using a version of Windows older than Windows-7 or want to install Python yourself.


Python is a computer scripting language, which means that one must have the Python interpreter installed on your computer to run a Python program. However, there are several Python packages required by GSAS-II that are not distributed within the standard Python distribution, so not just any version of the Python interpreter will do for GSAS-II unless compatible versions of the required packages are available.

  • Enthought Canopy is a Python distribution from a company that has done quite a bit of work in Python and made that available to the community. We have not done any testing with this for a while, but have done so in the past and expect it to work fine.
  • ActiveState ActivePython This is commercial licensed software that includes a free version with no support. ActiveState is well respected in the scripting community, but we have not tried this yet.

You should then be able to use the conda command to install GSAS-II following these instructions. With Windows Vista, you might be able to use a newer Python, but I have been unable to determine where Vista support was dropped.

Subversion & GSAS-II Sources

Subversion is a software version tracking system that allows you to download and update the GSAS-II software directly from the APS subversion server ( You can install a variety of different versions of this software, but the two we recommend for Windows are these:

  • If you are using the Anaconda Python distribution, then subversion is available as a conda package. Use command
    conda install svn
    to install it
  • TortoiseSVN incorporates Subversion capabilities into Windows. See the downloads directory and be sure to install the version (64-bit or 32-bit) appropriate for your version of Windows -- this must match the OS or it will not run. Once TortoiseSVN is installed, follow these installation instructions. If you do this, be sure to install the optional command line tools, otherwise you will need to manually update GSAS-II with the TortoiseSVN extensions to the file browser (not from the GSAS-II help/update menu command.)

or (not recommended)

or (really not recommended)

  • If you are unable to access the subversion server for some reason and must use a conventional download (note that in all the cases so far where people have been seemed to be blocked have turned out to be fixed through addition of a proxy server), you can download a snapshot of the current version of GSAS-II using this URL:

This will supply all the GSAS-II files in a zip archive. The contents of this archive can be moved to the location where GSAS-II will be installed.

We discourage use of this because you will need to repeat the entire download every time you want to upgrade; GSAS-II is updated often (sometimes daily!).

Compiling Fortran Code

Normally you will not need to compile anything. The GSAS-II distribution contains compiled .pyd (library modules) needed by a number of 32-bit and 64-bit configurations, but these files must match both the Python and Numpy major release number, so when installing your own versions there is a pretty good chance we will not have what you need pre-built. If you are working with an unsupported combination, compilation instructions can be found here.