Table 1.

Linear regression parameters and rms errors for the ¹H, ¹³C, ¹⁵N and ¹⁷O test sets using two-body fragment, cluster/fragment (with a 4 Å cluster), and GIPAW calculations. All cluster and fragment calculations employ the mixed basis, electrostatic embedding and a two-body fragment cut off of 6 Å. We recommend these scaling parameters be used for general applications.

		Two-body Fragment			Cluster/Fragment			GIPAW
Atom	Functional	RMSE	Slope	Intercept	RMSE	Slope	Intercept
Hydrogen	OPBE	0.34	−0.9391	29.28	0.36	−0.9324	29.05
	PBE	0.34	−0.9335	29.05	0.36	−0.9260	28.78	0.43	−0.8730	27.19
	TPSS	0.33	−0.9366	29.46	0.35	−0.9291	29.20
	TPSSh	0.33	−0.9294	29.27	0.35	−0.9238	29.07
	PBE0	0.34	−0.9169	28.69	0.35	−0.9111	28.49
	B3LYP	0.33	−0.9210	28.95	0.35	−0.9140	28.71
Carbon	OPBE	1.90	−1.0603	194.78	1.91	−1.0592	194.66
	PBE	2.09	−1.0273	180.43	2.12	−1.0240	180.25	2.18	−0.9902	169.19
	TPSS	2.16	−1.0442	185.91	2.21	−1.0419	185.75
	TPSSh	1.84	−1.0179	184.94	1.86	−1.0162	184.82
	PBE0	1.48	−0.9676	179.58	1.47	−0.9661	179.49
	B3LYP	1.51	−0.9702	173.83	1.52	−0.9685	173.70
Nitrogen	OPBE	6.11	−1.1296	215.63	6.52	−1.1067	215.41
	PBE	5.48	−1.0808	197.53	5.83	−1.0609	197.72	5.40	−1.0165	184.98
	TPSS	5.55	−1.1061	206.39	5.90	−1.0859	206.27
	TPSSh	4.97	−1.0797	205.63	5.26	−1.0616	205.52
	PBE0	4.20	−1.0201	197.84	4.06	−0.9997	197.15
	B3LYP	4.20	−1.0177	191.02	4.34	−0.9996	191.18
Oxygen	OPBE	11.01	−1.1461	278.91	8.85	−1.1347	281.53
	PBE	11.56	−1.1440	262.61	8.79	−1.1291	264.15	7.20	−1.0663	248.30
	TPSS	11.35	−1.1632	276.67	11.35	−1.1505	278.32
	TPSSh	10.63	−1.1265	278.45	8.33	−1.1153	280.05
	PBE0	9.80	−1.0607	270.18	7.55	−1.0502	271.60
	B3LYP	9.96	−1.0646	264.15	7.48	−1.0551	266.32