Algebraic approach to nonlinear molecular vibrations

Highly excited vibrational states of polyatomic molecules are known to have complicated level structures and exotic vibrational modes, which are caused by strong nonlinear interactions among normal modes. These physical systems have attracted great interests in recent years not only from traditional molecular spectroscopy and chemical reaction dynamics but also from the quantum-classical correspondence in nonlinear chaotic dynamics. In this article a Lie algebraic approach originated in nuclear physics is introduced and extended in molecular vibrational spectroscopy to be capable of treating the highly excited vibrational states. It is discussed how the extended theoretical model is used to extract the vibrational dynamics from experimental spectra. (author)