CRITICAL STUDY OF VIBRONIC INTERACTION CALCULATIONS

Abstract

A detailed study of the published non-empirical and semiempirical calculations of vibronic (vibrational-electronic) interactions in the 1B1u and 1B2u states of benzene is carried out. It is found that, in all but the most detailed non-empirical theory of vibronic interactions (Liehr and Moffitt 1957a), the Goeppert-Mayer and Sklar (1938) benzene electronic wave functions are too crude to adequately describe such interactions. Also, it is shown that the previously proposed semi-empirical theories of vibronic interactions (Craig 1950; Liehr 1955; Liehr and Moffitt 1957b; Murrell and Pople 1956) are derivable from the more exact theory of Liehr and Moffitt (1957a) only with the aid of rather "herculean" assumptions.