There is a strong correlation between the optimized parameters obtained in this study for solvent simulations and the volume of the substituents. (a) The ψsi,sj parameters can be decomposed into the sum ψsi,sj = −(ψsi + ψsj), where ψsi is strongly correlated with volume. (b) The ωsi,sj parameters are largely independent of sj, and are strongly correlated with the volume of si.