The results of a fully ab initio determination of the vibronic coupling strengths in ${\mathrm{C}}_{60}$ and ${\mathrm{C}}_{60}^{3\mathrm{-}}$ where the vibrational and the electronic structure are treated on an equal footing are presented. We obtain accurate vibrational frequencies and the corresponding coupling constants are obtained without further parameters. We find that the coupling to both the low- and high-frequency molecular modes are important, and their relevance to the Jahn-Teller effect and superconductivity are briefly discussed.

• Received 4 May 1993

DOI:https://doi.org/10.1103/PhysRevB.48.661