Ab initio study of the isomerization HNC → HCN. I. Ab initio calculation of the HNC ⇌ HCN potential surface and the corresponding energy levels

Abstract

The results of an ab initio SCF + CI calculation of the potential surface for the reaction HNC ⇌ HCN are presented. The approximative minimum-energy path is obtained minimizing the energy with respect to both stretching coordinates for a number of values of the bending coordinate θ. This potential curve is corrected by adding the zero-point energies corresponding to the stretching vibrations, assuming them to be θ dependent. The corresponding vibrational-rotational energy levels and wavefunctions are calculated using an appropriate vibration-rotation hamiltonian whereby the potential- and kinetic-energy terms, as well as the wavefunctions are represented by Fourier series in θ. © 1983.