Table 2.

Relative energies of the minima and selected high energy conformations as a function of the level of theory including extrapolation to the complete basis set.

Alpha	RIMP2/cc-pVTZ	RIMP2/cc-pVTZ	RIMP2/aug-cc-pVTZ	CBS
A, minimum	2.14	2.22	2.07	2.01
A, highE	5.12	4.90	4.89	4.89
BI, minimum	0.00	0.00	0.00	0.00
BI, highE	2.87	2.56	2.66	2.70
BII, minimum	2.57	2.98	2.77	2.69
BII, highE	5.14	6.05	5.29	4.96
Beta
A, minimum	2.18	1.65	1.63	1.62
A, highE	8.03	11.39	11.33	11.30
BI, minimum	0.00	0.00	0.00	0.00
BI, highE	6.90	5.69	5.85	5.92
BII, minimum	2.03	2.45	2.11	1.96
BII, highE	3.47	3.28	3.42	3.48
Gamma
A, minimum	2.15	2.26	2.07	1.99
A, highE	7.03	6.47	6.12	5.97
BI, minimum	0.00	0.00	0.00	0.00
BI, highE	5.94	5.44	4.99	4.79
BII, minimum	2.11	2.48	2.33	2.27
BII, highE	7.56	7.75	6.92	6.57
Epsilon
A, minimum	1.78	2.20	1.90	1.77
A, highE	2.16	2.56	2.21	2.07
BI, minimum	0.00	0.00	0.00	0.00
BI, highE	1.16	1.67	1.38	1.25
BII, minimum	1.91	2.56	2.10	1.91
BII, highE	2.54	3.03	2.75	2.63
Zeta
A, minimum	2.00	2.23	1.94	1.82
A, highE	4.73	5.82	4.81	4.39
BI, minimum	0.00	0.00	0.00	0.00
BI, highE	1.79	2.90	2.19	1.89
BII, minimum	1.02	0.93	0.82	0.77
BII, highE	2.85	3.22	2.95	2.83

All geometries at the MP2/6–31+G(d) level. Selected high energy conformations (highE) were 150, 135, 180, 270, and 150° for α, β, γ, ε, and ζ, respectively