Table 2.

Performance of the molecular mechanical models^*

No.	Model	BSSE-corrected MP2/aug-cc-pVTZ						MP2/aug-cc-pVTZ
		With original VDW parameters			With adjusted VDW parameters*			With original VDW parameters
		MaxE	AUE	RMSE	MaxE	AUE	RMSE	MaxE	AUE	RMSE
1	AA	6.71	1.13	1.67	6.84	0.85	1.54	7.45	1.82	2.30
2	AL	4.99	1.06	1.46	4.70	0.73	1.19	7.44	1.86	2.36
3	AE	5.76	1.03	1.42	5.47	0.70	1.12	7.44	1.86	2.35
4	AT	5.10	1.01	1.41	4.81	0.70	1.16	7.43	1.81	2.28
5	BA	7.35	1.17	1.80	7.40	0.93	1.73	7.35	1.74	2.26
6	BL	5.20	1.10	1.54	5.33	0.81	1.36	7.34	1.78	2.26
7	BE	5.80	1.06	1.48	5.51	0.78	1.28	7.35	1.76	2.23
8	BT	5.24	1.08	1.56	5.26	0.83	1.42	7.34	1.71	2.18
9	CA	8.38	1.41	2.22	8.73	1.26	2.25	7.31	1.83	2.38
10	CL	6.70	1.18	1.75	7.09	1.00	1.70	7.08	1.73	2.19
11	CE	6.35	1.23	1.83	6.81	1.06	1.81	7.09	1.70	2.17
12	CT	6.65	1.20	1.80	7.00	1.03	1.78	7.07	1.70	2.16
13	F94	12.50	2.22	3.73	11.99	1.75	3.40	14.44	3.25	4.70
14	F03	12.40	2.07	3.43	12.18	1.62	3.10	13.42	3.02	4.39

^*The following adjustments were made to the van der Waals parameters in MM including HO (the hydroxyl hydrogen) from (r₀ = 0, ε = 0) to (r₀ = 0.25, ε = 0.028), H (amine or amide hydrogen) from (r₀ =0.6, ε = 0.0157) to (r₀ = 0.65, ε = 0.0055), and CA (aromatic carbon) from (r₀ = 1.908, ε = 0.086) to (r₀ = 1.908, ε = 0.180).

MaxE: maximum error; AUE: average unsigned error; RMSE: root-mean-square error. All energies are in kcal/mol.