divide by zero encountered in scalar divide

[Hojeri]

Hi GSAS-II members, when I start the initial refinement, an error occurs"divide by zero encountered in scalar divide", what is the problem with this.

[briantoby]

@Hojeri This is very likely to be something wrong in your input, and cannot be diagnosed from just the error message above. There might be some other information in the console window that would provide a hint, but maybe not. OTOH a better error message would be helpful.

If you could post the .gpx file (place it in a .zip). I could see what is wrong. If it is work that you would rather not make public, please contact me by e-mail.

[Hojeri]

Hi @briantoby Thanks for your attention and I really appreciate it. I have uploaded the files in a zip. I am trying to fit the XRD pattern and get the phase fraction of Sm2Co17-H and Sm2Co17-R3m, the error message occur in the console as followed when I run the refinement.

SmCo_refinement.zip

[briantoby]

You can't use Rietveld like this. First, you should use the structures with their full symmetry. You will get errors like this if you try to vary a & b separately for a hexagonal cell (nor do you want to vary alpha, beta or gamma). Also, you should add parameters to the refinement slowly. Start with background and the scale factor and then add the cell parameters, etc.