Spectroscopic manifestation of conical intersections of potential surfaces of triatomic systems

Abstract

We have calculated the semiclassical shape of the absorption band for a triatomic complex of C2V symmetry, corresponding to an electronic transition from the non-degenerate ground-state and two excited states Ai, Bi (i=1, 2) when there exists a point of accidental degeneracy Ai=Bi. The analysis is done assuming that two normal vibrations are excited, one of which is nontotally symmetric. A comparison is made with the band of the\({\rm A}'\mathop \to \limits^{{\text{e}}'} {\rm E}'\) transition, characterizing optical absorption in Jahn-Teller systems.