This error is a result of the difficulty in producing Voronoi diagrams for crystals, and is likely caused by 1 or two different errors:
- Structure has atoms which are particularly far from each other. Our pymatgen implementation of the Voronoi tessellation relies on getting the atoms within a certain radius of the atom
for which you are computing the cell. If you increase that distance, some structures will tessellate without errors.
- Other. There are some structures that the tessellation fails for unknown reasons. Tessellations of crystals are difficult to compute due to some numerical issues resulting from calculating
whether >3 planes meet at a certain point, which are common in high-symmetry crystals. I’ve tried using multiple supercells of a structure or perturbing the atoms, but haven’t found anything that works consistently.
If you’d like, I can add in a setting to matminer that will allow you to increase the radius used in Voronoi calculation for StructuralHeterogeniety. In practice, I find that a few structures failing to tessellate doesn’t seriously impact