Berry phase of adiabatic electronic configurations in fullerene anions

Abstract

The selection rule on vibronic angular momentum of $t_{1u}^n \otimes h_g$ Jahn-Teller problem ($n = $ 1-5) is reinvestigated. It is shown that among three adiabatic orbitals only two have nonzero Berry phase. Thus, the Berry phase of adiabatic electronic configurations depends on the spin multiplicity as well as the number of electrons. On this basis, the general relation between the Berry phase and the angular momentum is described. It allows, in particular, to clarify the nature of vibronic states arising from high spin configurations. In comparison with the previous solution for the low-lying vibronic states for bimodal systems, the present solutions correctly fulfill all the symmetry requirement.