@yucongalicechen this may be too complicated and not worth the effort. Let's decide whether we want to do it before going ahead.

@yucongalicechen this may be too complicated and not worth the effort. Let's decide whether we want to do it before going ahead.

Okay yes I agree. I also found it's hard to pick a default density as the results are arranged differently between my local repo & github testing. Maybe a simpler solution here is to just reuse xraydb directly? It has a list of densities stored and user can manually input material density for unknown materials. We can differentiate material vs mass density if that makes things clearer.

I think it only has it for a few materials though. Are you saying it is too complicated to compute the density from the cif file, or too complicated to know which phase of a particular material is the right one to choose?