Table 4.

Interaction energies of a sodium cation with the models compounds as a function of orientation.

	Drude	ab initio	Difference
	Energy (kcal mol−1)	Energy (kcal mol−1)	Energy (kcal mol−1)
Pyridine
NZ in	−10.45	−12.30	1.85
NZ out	−6.62	−8.24	1.62
CG	−5.38	−7.12	1.74
CE1	−3.61	−5.17	1.57
Pyrimidine
N1 in	−7.89	−9.51	1.62
N2 out	−4.36	−5.32	0.96
C2	−4.49	−5.54	1.05
C4	−2.77	−3.61	0.84
Imidazole
NE2 in	−12.97	−14.97	2.00
NE2 out	−8.91	−9.75	0.84
CG	−4.77	−5.75	0.98
CD2	−5.70	−6.64	0.94
ND1	−3.15	−4.02	0.87
CE1	−7.81	−8.75	0.84

See Figure S1 of the supporting information for images of the sodium-model compound orientations.