MCSCF-CI calculations of infrared transition probabilities in the CH− and NH− ions

Abstract
Potential energy, electric dipole, and electronic transition moment functions have been calculated for several bound electronic states of CH and NH from accurate electronic wave functions. Spectroscopic constants for the X 2Π state of NH have been compared with the data recently obtained by laser induced autodetachment spectroscopy. Spectroscopic constants of the A 2Σ+ state of NH and radiative X 2Π–A 2Σ+ transition probabilities are presented. Spectroscopic constants and infrared transition probabilities for the X 3Σ and the a 1Δ states of CH have been calculated. The radiative lifetime of v=1 in CH(X 3Σ) is found to be in a very good agreement with a recent experimental value. The transition probabilities are for both ions much larger than those of their neutral counterparts, and increase in the series OH, NH, CH.