Table 3. Electron Densities (ρ_b) and Energy Densities (H_b) at Selected Bond Critical Points of 5–7 (H in Bold, Both in Atomic Units) and Delocalization Indices (DI) for U=E Bonds.

	5 (O)	6 (S)	7 (Se)
electron densities (ρ)	0.122	0.089	0.018
energy densities (H)	–0.118	–0.019	–0.010
delocalization indices (DI)	2.470	2.312	2.286