15min:

JEREMY ARMSTRONG, LOVORKA DEGORICIJA, ANTHONY HILDEBRAND, JESSICA KOEHNE AND PATRICK E. FLEMING, Department of Chemistry, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053.

The geometries and harmonic vibrational frequencies for the structural isomers of CN₂ and the corresponding cations have been calculated at the B3LYP/6-311+g(2df) level. Adiabatic ionization energies were calculated at the G1, G2(MP2) and G2 levels as well for each of the isomers. Of the cations, the linear molecule CNN⁺ is found to have the lowest energy. NCN⁺ (also linear) lies 0.2 eV higher in energy than CNN⁺. The other isomer of the cation, cyc-CN₂⁺, has a cyclic structure with C_2v symmetry and lies 0.8 eV higher in energy than CNN⁺. The adiabatic ionization energies of the radicals determined at the G2 level are IP(NCN) = 12.52 \pm 0.07 eV, IP(CNN) = 11.01 \pm 0.07 eV and IP(cyc-CN₂) = 11.94 \pm 0.07 eV.