How to perform and interpret a LeBail refinement on TOPAS

Ramon13

Although it was mentioned very briefly in the technical manual I'm wondering how to do a LeBail refinement in TOPAS GUI and Launch mode. The latter seems to give an output in JEdit but no key is given for how to describe the outputs so I'm unsure how to interpret it fully.

I'm doing this for my studies to better estimate the lattice parameters of mullite solid solutions in coal fly ashes. I would appreciate any help thank you! 🙂

johnsoevans

I didn't really understand your question. There's a tutorial on Pawley fitting on the topas site.
Pawley fitting is similar to Le Bail in that it is a structure-independent model, it just uses a slightly different least squares approach. In a hkl_Is fit TOPAS defaults to Pawley fitting. You can toggle between Pawley and Le Bail by adding "lebail 1" in the hkl_Is section of the INP file.