Vibronic coupling
From Biocrawler, the free encyclopedia.
Vibronic coupling is a branch of theoretical chemistry which deals with the interactions between electronic and nuclear motions of molecules. The term "vibronic" originates from the concatenation of the terms "vibrational" and "electronic". The word coupling denotes the idea that in a molecule, vibrational and electronic interactions are interrelated and influence each other.
Vibronic problems can be formulated in terms of second quantization commonly found in quantum mechanics. The problems deal with diabatic and adiabatic representations of potential surfaces of polyatomic molecules. It is common to deal with normal modes, and their associated ground and excited states.
Vibronic coupling can be used to deduce the electronic spectra of molecules from first principles. Perhaps the earliest demonstration of the importance of vibronic coupling was during the 1930's. Calculations of the lower excited levels of benzene by Sklar in 1937 (with the valence bond method) and later in 1938 by Goeppert-Mayer and Sklar (with the molecular orbital method) demonstrated a correspondence between the theoretical predictions and experimental results of the benzene spectrum. The benzene spectrum was the first qualitative computation of the efficiencies of various vibrations at inducing intensity absorption. [1]
References
1) Fischer, Gad. "Vibronic Coupling - The Interaction between the Electronic and Nuclear Motions", Academic Press, New York, 1984. ISBN 0-12-257240-8
