We further examined the outliers of the fine-tuned model on the pre-training test set reaction split. The top 20 reactions with the highest test errors are given in Supporting Information Table along with their gas phase barrier heights obtained from Grambow et al. It is found that the majority of the outliers are unusual reactions such as those forming biradical products, involving TSs with high ring strain, and with high barrier heights (E a > 85 kcal/mol). These reactions are unlikely to occur in real condensed phase systems, and therefore we anticipate the model to have lower errors on more feasible reactions. Overall, our model gives reliable predictions of solvent effects on numerous neutral reactions. The model is easy to use as only reaction and solvent SMILES are needed without requiring any additional computational steps. However, it should be highlighted that the proposed method is constructed based on some assumptions. We assume that the solvation effect does not change the 3D geometries of the reactant and TS. The training set is generated by performing single-point energy calculations in a solvent with the geometry of the lowestenergy conformer optimized in the gas phase, as provided by the original work of Grambow et al. and Harms et al., and potential conformational changes upon solvation were not considered. While prior studies indicate that the assumption generally gives acceptable predictions, conformer effects can be very crucial for the reactions involving compounds with many rotatable bonds, or zwitterions/tautomers and can lead to higher prediction errors. Figure illustrates the distribution of the ∆∆G ‡ solv errors per the number of rotatable bonds found in the reactant(s). While there is no clear correlation between the test error and the number of rotatable bonds, it can be seen that the majority of the reactants are rigid, with no or less than 4 rotatable bonds. Thus, future studies should focus on generating more thorough training set that contains more flexible and larger compounds and should consider various conformers of reactants, products, and TSs.