As an easy demonstration (even for non-crystallographers!), you can launch Fox, then use the top menu File->Load and open the example file example/pbso4-joint.xml. This is a file showing the global optimization of a very simple and well-known structure, PbSO4 (lead sulfate). Then:

  • Click on the Crystal tab, and in the window, choose the menu Display->3D Display. This opens a window with the crystal structure. You can click& drag with the mouse to rotate the structure

  • Click on the Powder Diffraction tab, and for the two PowderPattern objects, choose the menu Pattern->Show Graph. This will show you the current observed (blue) and calculated (red) patterns.

  • Click on the Crystal tab, and choose Parameters->Randomize Configuration (it would be too easy to start from the solution)

  • Click on the Global Optimization tab. Then choose Optimize->Run. This will launch the global optimization running. You will see the structure evolve, as well as the Cost functions (the two Chi^2^ in that case).