Chirality is specified depending on the sign of the previous dihedral angles. In cases where the central atom is sp 3 hybridized and the groups has 4 atoms, chirality inversion is possible. For simplicity, we set the probability of the dihedral angle being 2π/3 or -2π/3 to 0.5. In our dataset, MDQM9-nc, no other hybridizations occur, but our framework could be easily extended to other types of hybridizations such as sp 3 d or sp 3 d 2 , which are present in some drug-like molecules.