Table 4. The sum of weak-interaction energies involving N2A and O1A atoms as acceptors of hydrogen bonds.

	E N (kcal mol−1)	E O (kcal mol−1)	E sum
VA	0.00	−7.24	−7.24
(I)	−2.39	−20.41	−22.81
(II)	−5.46	−10.85	−16.31
(III)	0.00	−12.96	−12.96