Isotope Effects on Franckmdash;Condon Factors. VII. Vibrational Intensity Distribution in the H2Lyman, H2Werner, O2Schumannmdash;Runge, N2First Positive, N2Vegardmdash;Kaplan, and LiH (Amdash;X) Systems Based on RKR Potentials

摘要

Franckmdash;Condon factors, based on Rydbergmdash;Kleinmdash;Rees (RKR) potential functions, were computed for the H2and D2Lyman and Werner,16O2and18O2Schumannmdash;Runge,14N2and14N15N first positive and Vegardmdash;Kaplan, and7LiH and7LiD (Amdash;X) band systems. While the vibrational intensity distribution within several band series differs considerably from that previously computed using Morse potentials, the isotope effect is very similar by both methods. Only for the hydrogen Lyman bands, even the isotope effect on Franckmdash;Condon factors is markedly different by the two methods. The isotope ratio of Franckmdash;Condon factors,q(7LiH)/q(7LiD), in a given band progression (e.g.,vPrime;=3), oscillates between very large (104) and very small (10minus;2) values at the minima between the locus of the Condon parabolas. The isotope effect onrcentroids is negligible for transitions of oxygen and nitrogen molecules, but amounts to several percent for transitions of hydrogen and lithium hydride molecules. For the16O2Schumannmdash;Runge absorption bands, the variation of the electronic transition momentRewith internuclear distanceris represented byRe=const(1ndash;0.70r).