Valence bond studies of N5+

The results of STO-6G valence-bond studies are reported for the six pi-electrons of C-2v symmetry N-5(+), with pi-electron core charges determined from the valence bond structures. Important types of canonical Lewis structures are calculated to carry either three atomic formal charges, arranged spatially as (+), (-) and (+), as in [GRAPHICS] [GRAPHICS] or a single (+) atomic formal charge, as in the "long-bond" structure [GRAPHICS] When localized molecular orbitals are used to accommodate bonding electrons between pairs of adjacent atoms, each of these types of Lewis structures, and others, are components of the increased-valence structure :Nequivalent toNdivided byNdivided byNequivalent toN: whose bond properties are in qualitative accord with experimental estimates of the bond lengths for N-5(+) Consideration is also given to other types of valence bond representations for N-5(+), and the results of MP2 molecular orbital calculations for the hypothetical N-8(2+) are reported. For the latter species, a stable energy minimum with C-2 symmetry is obtained. Its bond lengths are related to those implied by a Lewis-type valence-bond structure.