GSAS is an excellent program for solving crystal structures. It also useful for solving simple magnetic structures. There is an excellent set of instructional materials available at APS courtesy of Brian Toby. You can download the program itself here.
Fullprof is another excellent program for refining crystal and magnetic structures. While it has a steep learning curve, it offers the ability to refine incommensurate magnetic structures which is lacking in GSAS.
Generally if you are interested in solving magnetic structures, I recommend you look at some of the material found here. Besides GBASIREPS found within Fullprof, I also recommend:
For windows, I would start by downloading the Python(x,y) distribution of python. It is large, but includes packages that many of you will find useful for scientific computing. I will assume that you download the whole distribution and install it as full. (For mac users, EPD) is another option.)
After you've installed python, I have developed a suite of programs for reducing neutron scattering data. However, in order to use the source code, you will need to have access to svn. For windows users, I suggest using Tortoise SVN. After installing it, you will need to reboot your machine. Next, create a c:\tripleaxisproject directory. Right click on the directory. You will see an option called Checkout SVN. Select that and in the resulting dialogue change the URL of the repository to: http://tripleaxisproject.googlecode.com/svn/trunk/
My students and I have also developed a set of libraries for analyzing spinwaves. Please look at the wiki to get started--there are even links to youtube videos!. You will want to checkout the source from this one in the same manner as above. However, this time make a directory, c:\spinwaves to hold the project locally. The URL of the repository is: http://spinwaves.googlecode.com/svn/trunk
You now need to tell python where these new directories are. If you've used the defaults, go to c:/python26/lib/site-packages/ and add the following files:
The data files for the tutorial are located in:
c:\tripleaxisproject\trunk\eclipse\src
Unzip this file and put the contents in:
c:\srfeas\20081212
During the tutorial, I showed you some simple code to solve a magnetic structure. To test that everything works, go to your start menu and select "run" and type "cmd.exe" which will open a command window. From there:
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