Considering again the original SM12 parameterization, it was found that the errors for the solvation free energy (both aqueous and non-aqueous) for the solute class containing molecular hydrogen, ammonia, water, and the water dimer were relatively large compared to the other solute classes . As already mentioned, the original SM12 parameterization pointed out a particular challenge with the self-solvation free energy of water which was predicted to be overly negative. To explore this further, we broke down ∆G solv i,j to cases where water was the solvent (j =water), water was the solute (i =water), and when neither the solvent or solute was water. Note that ∆G self i,i was not include in the set of ∆G solv i,j . This resulted in 104 systems wherein water was the solvent, 14 systems wherein water was the solute, and 1022 systems wherein water was neither the solvent or solute. A parity plot of the predicted versus reference values of ∆G solv i,j / (RT) with SM12 wherein these three cases are differentiated is provided in fig. . i,j / (RT) using the SM12 universal solvent model for the case where water was the solvent, water was the solute, and where water was neither the solvent or solute, as indicated. The blue lines corresponds to the y = x line, and the dashed blue lines correspond to ±1.1 and are drawn as a reference; the value of 1.1 was used based on the RMSE for the SM12 predictions. The reference values are from the Minnesota Solvation Database.