Check whether a crystal structure is already known

Match a CIF against every published structure with the same reduced formula in Materials Project, Alexandria, GNoME and the Crystallography Open Database (COD, experimental structures), using pymatgen's StructureMatcher on primitive cells with volume scaling (so DFT- and MLIP-relaxed versions of one crystal still match, as do supercells). Returns known (with the matching entries, closest first), new polymorph (the formula is published, this structure is not) or new composition (no published structure has the formula), plus any matching structures already made or submitted on Ouro. experimentally_known says whether a match was observed experimentally: a COD entry, or a Materials Project entry MP counts as experimental (with the ICSD collection codes MP matched it to). New means absent from these databases, not from the literature. Rejects overlapping-atom CIFs unless bypass_cif_health_screen is set.