Space group Pbnm / Pnma (62) (Bug or not?)

Materials Project
1

I was looking for the structure of TbMnO3 (mp-22055) and Material Project told me it has space group Pnma. However, papers such as \url{https://www.nature.com/articles/nature02018} denote it as Pbnm.
The two are indeed the same space group, but with a different convention of the axes, namely abc of Pbnm is cab of Pnma. But the lattice constants indicate MP and the papers are using same axis but different space group notations.

I wonder which one is wrong, MP, the papers or me. I’ll be grateful if someone can explain this to me!

2

This is likely a bug in MP. We use the spglib code get the spacegroup of the cell, but as of right now don’t set the lattice into the most appropriate convention for whatever spglib reports. I’ll note this as something we need to fix. Thanks for pointing this out~

3

Thanks a lot :slight_smile: :stuck_out_tongue_closed_eyes: