The correlation between ∆G •, ‡ and the inter scoring energy is comparably strong with a Pearson correlation coefficient of 0.95, see Figure . Again, the Spearman correlation coefficient of 0.97 is high and shows that the molecules can be successfully ranked according to their ∆G •, ‡ by the inter scoring function. For four out of the 52 molecules, the intermediate-scoring energy could not be calculated since the catalyst reacts with the oxygen-atom of the carbonyl-moiety of intermediate 2. The reaction mechanism as studied by Liu et al. relies on this moiety in the rate-determining step and all molecules that react with the carbonyl-moiety are deemed ineffective catalysts and are assigned an overall score of 0.