Collect. Czech. Chem. Commun. 2008, 73, 873-897

Energies and Electric Dipole Moments of the Bound Vibrational States of HN2+ and DN2+

Vladimír Špirkoa,b, Ota Bludskýb and Wolfgang P. Kraemerc,*

a Department of Applied Mathematics and Department of Chemistry, University of Waterloo, Ontario N2L 3G1, Canada
b Center for Biomolecules and Complex Molecular Systems, Institute of Organic Chemistry and Biochemistry, v.v.i, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
c Max Planck Institute of Astrophysics, Postfach 1317, D-85741 Garching, Germany


The adiabatic three-dimensional potential energy surface and the corresponding dipole moment surface describing the ground electronic state of HN2+1Σ+) are calculated at different levels of ab initio theory. The calculations cover the entire bound part of the potential up to its lowest dissociation channel including the isomerization barrier. Energies of all bound vibrational and low-lying ro-vibrational levels are determined in a fully variational procedure using the Suttcliffe-Tennyson Hamiltonian for triatomic molecules. They are in close agreement with the available experimental numbers. From the dipole moment function effective dipoles and transition moments are obtained for all the calculated vibrational and ro-vibrational states. Statistical tools such as the density of states or the nearest-neighbor level spacing distribution (NNSD) are applied to describe and analyse general patterns and characteristics of the energy and dipole results calculated for the massively large number of states of the strongly bound HN2+ ion and its deuterated isotopomer.

Keywords: Potential energy and electric dipole hypersurfaces; Ab initio CCSD(T) calculations; Effective dipoles and transition moments; Density of states and nearest-neighbor level spacing distributions; Astrochemistry; Interstallar ions.

References: 42 live references.