TABLE II.
The performance of new AM1-BCC charges with GAFF2 parameters on the solvation free energies of neutral organic solvent–neutral organic solute pairs. Expt. stands for experimental; MSE stands for mean signed error; MUE stands for mean unsigned error; RMSE stands for root mean square error; PI stands for predictive index; R stands for Pearson’s correlation coefficient; k and b stand for the slope and intercept values, respectively, when fitting the calculated data (y) vs experimental data (x) with function y = kx + b.
| Data | Expt. data | MSE | MUE | RMSE | b | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Solvents | Solutes | No. | range (kcal/mol) | (kcal/mol) | (kcal/mol) | (kcal/mol) | PI | R | k | (kcal/mol) |
| CH | CH | 54 | 5.41 | −0.26 | 0.46 | 0.57 | 0.93 | 0.93 | 1.09 | 0.16 |
| CH | CHO | 295 | 8.44 | −0.01 | 0.50 | 0.62 | 0.93 | 0.93 | 1.12 | 0.58 |
| CH | CHN | 83 | 5.77 | 0.71 | 0.81 | 0.96 | 0.95 | 0.95 | 1.11 | 1.21 |
| CH | CHON | 20 | 7.12 | 0.31 | 0.41 | 0.58 | 0.98 | 0.97 | 0.97 | 0.15 |
| Alkanes | CHS | 5 | 2.54 | 0.17 | 0.51 | 0.54 | 0.89 | 0.95 | 1.36 | 1.59 |
| Alkanes | CHCl | 14 | 2.95 | −0.13 | 0.26 | 0.29 | 0.99 | 0.97 | 0.91 | −0.56 |
| Alkanes | CHF, CHI, CHBr | 13 | 4.07 | −0.23 | 0.31 | 0.46 | 0.91 | 0.94 | 0.91 | −0.69 |
| Ethers | CH | 16 | 3.04 | −0.21 | 0.35 | 0.42 | 0.89 | 0.93 | 1.12 | 0.45 |
| Ethers | CHO | 39 | 11.03 | −0.23 | 0.46 | 0.58 | 0.98 | 0.97 | 0.98 | −0.38 |
| Ethers | CHN | 23 | 4.35 | 0.03 | 0.44 | 0.53 | 0.96 | 0.94 | 1.11 | 0.51 |
| Ethers | CHON | 10 | 6.93 | −0.45 | 0.61 | 0.73 | 1.00 | 0.96 | 0.90 | −1.00 |
| Alcohols | CH | 54 | 7.48 | −0.16 | 0.43 | 0.54 | 0.93 | 0.95 | 1.07 | 0.08 |
| Alcohols | CHO | 96 | 10.30 | −0.08 | 0.59 | 0.73 | 0.97 | 0.95 | 1.03 | 0.10 |
| Alcohols | CHN | 55 | 5.28 | 0.45 | 0.59 | 0.75 | 0.91 | 0.89 | 1.04 | 0.68 |
| Alcohols | CHON | 16 | 8.26 | −0.10 | 0.22 | 0.31 | 1.00 | 0.99 | 0.96 | −0.34 |
| Ketones | CH | 5 | 3.21 | −0.26 | 0.46 | 0.50 | 0.67 | 0.94 | 1.06 | 0.03 |
| Ketones | CHO | 9 | 5.26 | −0.59 | 0.60 | 0.69 | 0.98 | 0.98 | 1.00 | −0.61 |
| Ketones | CHN, CHON | 6 | 4.68 | −0.11 | 0.32 | 0.37 | 1.00 | 0.99 | 0.79 | −1.11 |
| Esters | CH | 3 | 2.87 | −0.23 | 0.34 | 0.38 | 0.89 | 0.98 | 1.03 | −0.08 |
| Esters | CHO | 26 | 6.24 | −0.42 | 0.45 | 0.53 | 0.98 | 0.98 | 0.99 | −0.48 |
| Esters | CHN, CHON | 6 | 2.75 | 0.12 | 0.23 | 0.30 | 0.98 | 0.97 | 0.93 | −0.32 |
| CHN | CH | 8 | 2.14 | −0.12 | 0.43 | 0.50 | 0.65 | 0.66 | 0.67 | −1.71 |
| CHN | CHO | 22 | 5.23 | −0.26 | 0.55 | 0.63 | 0.97 | 0.92 | 0.85 | −1.07 |
| CHN | CHN, CHON | 9 | 3.98 | −0.21 | 0.59 | 0.66 | 0.85 | 0.87 | 0.58 | −2.55 |
| CHON | CHON | 8 | 3.14 | −0.31 | 0.32 | 0.44 | 0.99 | 0.99 | 1.20 | 0.94 |
| Summary | 895 | 12.87 | 0.01 | 0.51 | 0.65 | 0.95 | 0.94 | 1.06 | 0.31 |