Table 4.

Relative energy in the gas phase^a (ΔE_gp) calculated at different theoretical levels^b for the minimum energy conformations of Ac-t-l-c₆Phe-NHMe.

#	6-31+G(d,p)			6-311++G(d,p)
	B3LYP	MP2	HF	B3LYP
1	0.0c	0.0d	0.0e	0.0f
2	2.7	2.0	2.3	2.6
3	3.5	2.6	3.7	3.4
4	4.1	3.0	2.2	3.9
5	4.3	1.5	3.0	4.2
6	5.9	4.1	7.3	5.9
7	6.0	4.2	4.3	5.8
8	6.2	6.0	3.4	4.7
9	6.9	6.7	6.2	6.7
10	7.4	7.1	6.0	6.9
11	7.4	5.7	6.4	7.1
12	9.3	7.7	10.5	9.2
13	9.3	7.7	11.0	9.3
14	10.3	9.9	12.1	10.0
15	11.5	10.6	12.9	11.4
16	13.2	12.9	14.0	12.9
17	13.3	13.2	13.3	13.0
18	13.5	12.7	12.9	13.2
19	13.6	12.1	13.4	13.3
20	14.4	12.4	13.6	14.2
21	14.6	12.3	14.6	14.4

^aIn kcal/mol.

^bEnergies at the MP2/6-31+G(d,p), HF/6-31+G(d,p) and B3LYP/6-311++G(d,p) levels were derived from single point calculations on B3LYP/6-31+G(d,p) geometries.

^cE=−883.014189 a.u.

^dE=−880.351683 a.u.

^eE=−877.424807 a.u.

^fE=−883.195613 a.u.