Vibronic Spectra in Improved Versions of the Theory

Abstract

We now turn to improved models. The calculations are substantially more complicated and for clarity one uses the most powerful methods presently known for solving quantum-mechanical problems in solid state physics. The development of these methods goes beyond the scope of this text. We limit ourselves here to a discussion of the results, referring the reader to the original papers for further details. We will consider deviations from the Condon approximation in somewhat more detail. In Appendix III we give several formulas useful in calculating and summing Franck — Condon factors in combinations which arise in the theory of quasiline spectra. Deviation from the Condon approximation will be used to illustrate the use of these formulas.