As described in the Computational Methodology section, the GB-GM method grows a molecule one atom at a time where the choice of bond order and atom type is chosen probabilistically based on a bonding analysis of the first 1000 molecules in the ZINC dataset (referred to hereafter as the reference set). The GB-GM model is tested by generating 1000 molecules using ethane as the "seed" molecule (which takes about 30 seconds on a laptop) and repeating the statistical bonding analysis. The average molecular size in the new data set is 23.2±4.1 atoms, which is nearly identical to the that of the training set: 23.2±4.4 atoms. There are 2498 rings compared to 2768 in the reference set and 59% of the atoms are in rings, which also is close to 63% in the reference set. 41% of the 3-atom combinations in rings is C=C-C, which is reasonably close to the 45% in the reference set (Table ) This difference is probably due to the fact that at least one of the two carbons must be secondary to "accept" the double bond, and if such a bonding pattern is not present then no "=C-" atom will be added. It is thus a little bit more likely that a "-C-" atom will be "accepted", compared to a "=C-" atom.