Jahn-Teller spectral fingerprint in molecular photoemission : C-60

The h(u) hole spectral intensity for C-60-->C-60(+) molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 H-g, 6 G(g), and 2 A(g) 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 C-60, is shown to measure directly and rather generally the strength of the final-state Jahn-Teller coupling.