Theoretical investigations of small multiply charged cations. III. NeN ²⁺

Abstract

First-order configuration-interaction calculations based on 4-6 σ, 1-2 π complete active space self-consistent-field reference wave functions are reported for the potential-energy curves of the 21 lowest-lying electronic states of NeN2+ which dissociate into (2P)Ne+ + (3P)N+ or (2P)Ne+ + ( 1D)N+. Using the same complete active space self-consistent-field SCF reference function, second-order configuration- interaction wave functions have been calculated for the X 2Π ground state of NeN2+. At this level the potential minimum lies 4.57 eV above the (3P)N+ + (2P)Ne+ dissociation limit and there is a barrier to dissociation of 0.94 eV. All other states of NeN2+ are either repulsive, or exhibit a flat potential curve at some closer interatomic distance. In addition, the X 3Σ- ground-state potential-energy curve of single charged NeN+ was computed at the complete active space SCF + second-order configuration-interaction level. The dissociation energy is predicted as De = 0.47 eV at re = 3.30 a0. Bonding in NeN2+ and NeN+ is discussed in terms of donor-acceptor interactions between Ne and N2+ or N+, respectively. [For paper II of this series see W. Koch and G. Frenking, J. Chem. Phys. 86, 5617 (1987).] © 1990 American Institute of Physics.