On the c3Π ( v = 0) state of carbon monoxide

Abstract

A full analysis of the near infrared c 3Π– b 3Σ + (0–0) band is given and term values for both states determined. The c 3Π ( v = 0) state was jointly analysed with the perturbing k 3Π ( v = 2) state and data from the c 3Π– X 1Σ + (0–0) transition and 3 A band system were included. It is shown that the available data are consistent with the c 3Π ( v = 0) state having near Hund’s case b coupling with a spin–orbit constant of A = 0.45 ± 0.02 cm −1, a homogeneous perturbation with the k 3Π ( v = 2) state, and Λ-type doubling arising predominantly from its interaction with the j 3Σ + state. A discrepancy with a more recent report of the 3 A band system is identified and discussed. The perturbed b 3Σ + state term values are consistent with a previously reported five state interaction model.