Scientific highlight 4

The PES of vapor-phase C60, as measured by Canton et al. [1] and by Bruhwiler et al. [2], compared with calculation based on a Lanczos determination of the Green's function of the hole created in the highest occupied molecular orbital, and taking into account its interaction with the molecular vibrational modes. The calculation takes the vibrational frequencies and electron-vibration couplings from the ab-initio determination of Ref. [3], and samples randomly the thermal population of the initial molecular vibrational states at the experimental temperature T=800 K. All spectra are shifted to have the main peak at zero energy. The two main structures reflect the 0-vibron and 1-vibron lines of the two high-frequency Hg modes below 200 meV, and suffer a blue shift characteristic of the dynamical Jahn-Teller effect due to the degenerate orbital state of the hole. The broad global nature of the spectrum is mostly related to many-vibration incoherent excitations of the strongly-coupled low-energy Hg mode (after N. Manini et al., Phys. Rev. Lett. 91, 196402 (2003) ) .

[1] P. Bruhwiler et al., Chem. Phys. Lett. 279, 85 (1997).
[2] S. E. Canton et al., Phys. Rev. Lett. 89, 045502 (2002).
[3] N. Manini et al., Philos. Mag. B 81, 793 (2001).