Table 3. Experimental pKa, Mean Absolute Error (MAE), Standard Deviations (Std. Dev.), and the Largest Positive (Max) and Negative (Min) Deviation at HF and DFT Levelsa.
| Training Set 1 | ||||||||
|---|---|---|---|---|---|---|---|---|
| HF | LSDA | PBE | B3LYP | CAM B3LYP | WB97XD | M062X | B2PLYP | |
| MAE | 1.10 | 0.39 | 1.04 | 1.07 | 1.06 | 1.07 | 0.82 | 0.93 |
| std. dev. | 0.88 | 0.33 | 1.00 | 0.86 | 0.87 | 0.86 | 0.74 | 0.90 |
| max | 4.37 | 1.43 | 5.04 | 4.42 | 4.30 | 4.33 | 3.85 | 4.50 |
| min | –2.04 | –1.12 | –1.96 | –1.58 | –1.79 | –1.72 | –1.17 | –1.70 |
| Training Set 2 | ||||||||
|---|---|---|---|---|---|---|---|---|
| HF | LSDA | PBE | B3LYP | CAM B3LYP | WB97XD | M062X | B2PLYP | |
| MAE | 1.10 | 0.39 | 1.15 | 1.23 | 1.17 | 1.43 | 0.96 | 1.07 |
| std. dev. | 1.15 | 0.34 | 1.23 | 1.27 | 1.16 | 1.32 | 1.05 | 1.13 |
| max | 5.10 | 1.48 | 5.91 | 5.53 | 5.21 | 5.71 | 4.76 | 5.36 |
| min | –1.30 | –1.07 | –1.09 | –0.47 | –0.87 | –0.34 | –0.27 | –0.83 |
| Training Set 3 | ||||||||
|---|---|---|---|---|---|---|---|---|
| HF | LSDA | PBE | B3LYP | CAM B3LYP | WB97XD | M062X | B2PLYP | |
| MAE | 1.08 | 0.49 | 1.09 | 1.04 | 1.09 | 1.13 | 0.85 | 0.93 |
| std. dev. | 0.97 | 0.38 | 1.17 | 0.96 | 1.01 | 1.11 | 0.92 | 0.97 |
| max | 4.71 | 1.07 | 5.73 | 4.77 | 4.86 | 5.11 | 4.45 | 4.87 |
| min | –1.69 | –1.47 | –1.27 | –1.22 | –1.22 | –0.94 | –0.58 | –1.32 |
a
All calculations were carried out with the SMD model, aug-cc-pVTZ basis set, and training sets 1, 2, and 3.