Vibronic coupling in C60- anion revisited: Derivations from photoelectron spectra and DFT calculations

The vibronic coupling constants of C-60(-) are derived from the photoelectron spectrum measured by Wang et al. [J. Chem. Phys. 123, 051106 (2005)] at low temperature with high resolutions. We find that the couplings of the Jahn-Teller modes of C-60(-) are weaker than the couplings reported by Gunnarsson et al. [Phys. Rev. Lett. 74, 1875 (1995)]. The total stabilization energy after h(g) and a(g) modes is reduced with respect to the previous derivation of Gunnarsson et al. by 30%. The computed vibronic coupling constants using density-functional theory with B3LYP functional agree well with the new experimental constants, so the discrepancy between theory and experiment persistent in the previous studies is basically solved.