Is there a stable B2Π state for the CNO molecule?

Abstract

We report MRD-CI calculations on the ground state X 2Π and the excited states A 2Σ + and B 2Π of the CNO molecule in linear geometry. The surfaces for oxygen and carbon extraction are calculated using a limited CI expansion of 47 configuration state functions; in the vicinity of the minima obtained with this procedure large-scale CI calculations are carried out including deter-mination of the spin-orbit splitting of the 2Π states of the minima. We find that the B 2Π state will be difficult to detect spectroscopically due to an avoided crossing just at the equilibrium geometry of the ground state at R CN = 2.25 a.u., R NO = 2.30 a.u. Accordingly we find two shallow minima for B 2Π at R CN = 2.33 a.u., R NO = 2.91 a.u. and R CN = 2.78 a.u., R NO = 2.28 a.u., respectively.