Table 5. B3LYP/6-311++G**-Calculated Natural Coulombic Potential Energy (V_NCE) and its Lewis [E(L)] and Non-Lewis [E(NL)] Components (in au) and also Their Corresponding Differences for the Axial and Equatorial Conformations of Compounds 1–3^b.

	NBO-B3LYP/6-311++G**
	1		2		3
	ax	eq	ax	eq	ax	eq
E(es)(L)	–0.40435	–0.39341	–0.36185	–0.34828	–0.36954	–0.35619
ΔE(es)(L)	–0.01094(−6.86)a	0.00000	–0.01357(−8.52)a	0.00000	–0.01335(−8.38)a	0.00000
E(es)(NL)	0.01801	0.02026	0.00303	0.00069	0.00250	–0.00092
ΔE(es)(NL)	–0.00225(−1.41)a	0.00000	0.00234(1.47)a	0.00000	0.00342(2.15)a	0.00000
VNCE	–0.38634	–0.37315	–0.35882	–0.34759	–0.36704	–0.35712
ΔE(es)	–0.01319(−8.28)a	0.00000	–0.01123(−7.05)a	0.00000	–0.00992(−6.22)a	0.00000

^aValues are in kcal mol^–1.

^bΔE^(es) = V_NCE(C_2h) – V_NCE(D_2h).