The mutual perturbations of A 1Σu+ (v = 2) and B 1Σu+ (v = 0) levels of As2 molecule

Abstract The perturbations which appear in (2–14) and (2–15) bands of A 1 Σ u + -X 1 Σ g + system of As 2 , as well as in (0–5) and (0–6) bands of B 1 Σ u + -X 1 Σ g + system, are studied and shown to be due to a mutual interaction between A ( v = 2) and B ( v = 0) levels. A deperturbation procedure, including only these two levels, leads to the following deperturbed rotational constants: B state, B 0 = 0.07023 cm −1 ; A state, B 2 = 0.07813 cm −1 . The perturbation matrix element is found to be H = 14.25 cm −1 .