GSAS : YES! - at present the only effective Rietveld system for these types of large problems
GSAS (by the Anna Karenina principle - a happy family):
Can handle large numbers of atoms and restraints
Large variety of restraints
Menu based control amenable to scripts and automation
Easy enabling and disable of histograms
Integrated Fourier map including peak search
TOF Neutron / EDX as well
- Other Rietveld Programs affected by one or more of the following problems
- Cannot handle large numbers of atoms or restraints
- Don’t have many types of restraints
- Manual editing of ASCII files or GUIs that do not easily allow quick changes to large numbers of atoms
- Problematic enabling and disabling of restrains and histograms
- No integrated Fourier map generation and viewing
- Can only handle constant wavelength neutron and angular dispersive X-ray diffraction data.