Table 7. Mean Absolute Errors of the Interaction Energies (kcal/mol) for the S22 and S66×8 Benchmark Sets from Single-Point PM7 and OMx-Dn Calculations at the Reference Geometries.

		method
			OM2			OM3
subset	N	PM7	D2	D3	D3T	D2	D3	D3T
S22
overall	22	0.76	1.16	0.91	0.94	1.25	0.99	0.97
hydrogen bonded	7	0.73	2.32	2.17	2.15	2.65	2.30	2.28
mixed	7	0.70	0.40	0.27	0.28	0.79	0.47	0.50
dispersion	8	0.85	0.81	0.36	0.47	0.44	0.29	0.24
S66×8
overall	528	0.73	0.96	0.78	0.79	0.88	0.69	0.71
electrostatic	184	0.91	1.54	1.43	1.43	1.48	1.30	1.30
mixed	160	0.55	0.52	0.37	0.37	0.53	0.33	0.34
dispersion	184	0.69	0.77	0.49	0.52	0.59	0.41	0.43