Qualitative intramolecular quantum dynamics
Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, ul. Ulyanova 46, Nizhny Novgorod, 603000, Russian Federation
The state-of-the-art symmetry methods for the consistent quantum-mechanical treatment of intramolecular motions are reviewed. It is shown that for a broad class of topical problems, these methods are not only self-sufficient but, at present, the only possible ones. In particular, they greatly simplify the analysis of nonrigid molecules, for which conventional, analytical equation-of-motion methods run into serious mathematical difficulties even at low excitation energies.