Kohei Shinohara

Let me mention that `StructureMatcher.group_structures` calls `_preprocess` for each structure only once (https://github.com/materialsproject/pymatgen/pull/2490). So, it is a little improvement, but using `StructureMatcher.group_structures` will reduce `_preprocess` part of the flame graph...

It seems the segmentation fault is caused by magmom and high symprec(~=1e-2) from spglib. I've opened the corresponding issue page linked above. For now, dropping magmom entries from `Structure` will...

Now, I believe this issue will be solved with spglib==2.0.1.

As spglib developer side, I think it may be possible that spglib returns another space group for a supercell than that for the primitive structure. Spglib only returns rotation matrices...

Excuse me for interrupting. I am a maintainer of spglib. It seems the POSCAR structure is rather distorted from C2/m. The following script shows a detected space group type depends...

@esoteric-ephemera For the first case of this issue, the distinction between Cm and C2/m would be challenging for such a large symprec. It may be helpful to check atoms are...

@jmmshn I could not reproduce your result with spglib==2.3.1 and pymatgen==2024.1.27. If your error still presents in the latest, please open an issue at spglib. In that case, please use...

For our side, I try the following POSCAR ("Si.POSCAR"): ``` system Si 5.430 0.5 0.5 0.0 0.0 0.5 0.5 0.5 0.0 0.5 2 cart 0.00 0.00 0.00 0.25 0.25 0.25...