Jahn-Teller distortions and excitation energies in Cn60+

Based on previously computed parameters for the electron-phonon couplings and the Coulomb exchange, we compute and classify the static Jahn-Teller (JT) distortions, i.e., the minima of the lowest adiabatic potential energy surface, of C60n+, for all values of charge 1≤n≤9 and spin. We compute the intra-band electronic excitation energies in the different optimal geometries in the sudden approximation, and find a spread of the electronic states of roughly 1 eV. We also obtain the leading vibronic quantum corrections to the ground-state energy, equal to zero-point energy lowering due to the softening of the phonons at the adiabatic JT minima: these nonadiabatic corrections are so large that for 4≤n≤6 states of different spin symmetry turn lower than the high-spin adiabatic ground state. © 2003 Elsevier B.V. All rights reserved.