Theoretical study of homogeneous perturbations. II. Least-squares fitting method to obtain "deperturbed" crossing Morse curves. Application to the perturbed 1Σu+ states of N2

Abstract

A method to obtain a "deperturbation" of perturbed vibrational levels is developed. The vibrational functions associated with two (or three) crossing Morse curves are used to set up an interaction matrix. The eigenvalues of this matrix are compared with the observed levels and the "deperturbed" Morse curves are obtained by a least-squares fitting. This method applied to the ¹Σ_u⁺ states of N₂ confirms the interpretation given by Dressler (following paper).