A theoretical study of the rovibronic spectra of CNO, NCO and CON

Abstract

Variational calculations of the rovibronic spectra of the three isomers NCO, CNO and CON in their X2Π electronic ground state have been performed. The calculations were done in an attempt to calibrate a computed ab initio potential, based on the complete active space second-order perturbation theory (CASPT2) approach, against experimental vibrational data. Comparison with experiment for the NCO isomer indicates that the theoretical potential is a little flat. It is shown that minor changes to the quadratic force field parameters lead to a substantial improvement in the accuracy.