Error in Structure (mp-1271128)

Materials Project
1

I found some error in https://next-gen.materialsproject.org/materials/mp-1271128?chemsys=Fe.
The Space Group/Symbol, International Number, and Point Group show I4/mmm, 139, and 4/mmm. However, in Description, it shows Fmmm space group. Also, in the simulated Diffraction Pattern, it shows a typical Fmmm XRD.
Based on the lattice parameter, mp-1271128 should be Fmmm rather than I4/mmm.

2

Hi @CcJacky please take a look at this answer to a related question. The short answer is that we automatically determine symmetry information, which is not an exact methodology. Using a lower/stricter tolerance gives the Fmmm spacegroup, using a looser tolerance gives I4/mmm:

from mp_api.client import MPRester

with MPRester() as mpr:
  s = mpr.get_structure_by_material_id('mp-1271128')

for symprec in (0.1, 0.01): # 0.1 is looser, 0.01 is tighter
  print(symprec,s.get_space_group_info(symprec=symprec)[0])
>>> 0.1 I4/mmm
>>> 0.01 Fmmm
1 Like