Vibronic states in conical intersections: manifestations of centrifugal energy and non-adiabaticity in optical spectra of Jahn-Teller systems

Quantum states in conical intersections of adiabatic potentials in Jahn-Teller systems, known as Slonczewski resonances, are considered. It is shown that centrifugal forces associated with the rotation of the Jahn-Teller deformation (pseudorotation) play an important role in these resonances causing appearance of gaps in the energy spectrum of these states. In addition, the decay of these states, caused by non-adiabaticity, decreases with increasing angular momentum of the pseudorotation. As a result, states with a large momentum acquire a long lifetime. The optical spectra of the A ₁→E electronic transition with different values of the pseudorotational angular momentum are presented. In these spectra, centrifugal energy gaps and the stabilization of levels with a large pseudorotation momentum are clearly identified. (paper)