A simple method to determine bond lengths and excited state surfaces from electronic-vibrational spectra

Abstract

A fast and efficient method using the spectral moments of an electronic-vibrational spectrum is described to determine the harmonic and Morse potential fits to the excited state potential in the Franck-Condon region. Some of the drawbacks of the Franck-Condon least-squares fitting procedure are overcome by the moment method. The method is applied to some diatomics of current interest, spanning a wide range of bond length change in the electronic transition. The accuracy of the results suggests that the spectral moment method can be a replacement for the traditional and still popular Franck-Condon analysis. © 1990.