The hu hole spectral intensity for C60 → C + 60 molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 Hg, 6 Gg, and 2 Ag mode couplings. The computed spectrum at 800 K is in striking agreement with gas-phase data. The energy separation of the first main shoulder from the main photoemission peak, 230 meV in C60, is shown to measure directly and rather generally the strength of the final-state Jahn-Teller coupling.

We investigate the occurrence of Hund's rule magnetism in C n± 60 molecular ions, by computing the ground-state spin for all charge states n from −3 to +5. The two competing interactions, electronvibration (e-v, including Jahn Teller, favoring low spin) and electron-electron (e-e, including Hund-rule exchange, favoring high spin), are accounted for based on previously computed ab-initio coupling parameters. Treating the ion coordinates as classical, we first calculate and classify the static Jahn-Teller distorted states for all n, inclusive of both e-v and e-e effects. We then correct the adiabatic result by including the zero-point energy lowering associated with softening of vibrations at the adiabatic Jahn-Teller minima. Our overall result is that while, like in previous investigations, low-spin states prevail in negative ions, Hund's rule high spin dominates all positive C n+ 60 ions. This suggests also that Hund-rule magnetism could arise in fullerene cation-based solid state compounds, particularly those involving C 2+ 60 .PACS. 36.40.Cg Electronic and magnetic properties of clusters -61.48.+c Fullerenes and fullerene-related materials (structure) -71.20.Tx Fullerenes and related materials; intercalation compounds (electronic structure) -75.75.+a Magnetic properties of nanostructures