Table 3.
Accuracy of various QM methods for predicting noncovalent interactions
| Functional | Total | HB6/04 | CT7/04 | DI6/04 | WI7/05 | PPS5/05 |
|---|---|---|---|---|---|---|
| DFT | ||||||
| M06-2X* | 0.30 | 0.45 | 0.36 | 0.25 | 0.17 | 0.26 |
| XYG3† | 0.32 | 0.38 | 0.64 | 0.19 | 0.12 | 0.25 |
| M06* | 0.43 | 0.26 | 1.11 | 0.26 | 0.20 | 0.21 |
| M06-L* | 0.58 | 0.21 | 1.80 | 0.32 | 0.19 | 0.17 |
| B2PLYP† | 0.75 | 0.35 | 0.75 | 0.30 | 0.12 | 2.68 |
| B3LYP† | 0.97 | 0.60 | 0.71 | 0.78 | 0.31 | 2.95 |
| PBE‡ | 1.17 | 0.45 | 2.95 | 0.46 | 0.13 | 1.86 |
| BLYP‡ | 1.48 | 1.18 | 1.67 | 1.00 | 0.45 | 3.58 |
| LDA‡ | 3.12 | 4.64 | 6.78 | 2.93 | 0.30 | 0.35 |
| Ab initio | ||||||
| HF† | 2.08 | 2.25 | 3.61 | 2.17 | 0.29 | 2.11 |
| MP2‡ | 0.64 | 0.99 | 0.47 | 0.29 | 0.08 | 1.69 |
| QCISD(T)‡ | 0.57 | 0.90 | 0.62 | 0.47 | 0.07 | 0.95 |
MADs in kcal/mol for the 31 cases in the Truhlar web site DB (14, 15), which contains the best available information from ab initio calculations of noncovalent interactions (NCIE31/05). This consists of 6 HB complexes, 7 CT complexes, 6 DI complexes, 7 WI complexes, and 5 PPS complexes. The WI and PPS are dominated by London dispersion.
*Data are from ref. 14.
†Our calculations used the 6-311+G(3df,2p) basis sets with geometries from the Truhlar DB web site. Counterpoise corrections for possible basis set superposition errors were not included.
‡Data are from ref. 15.