Jahn-Teller effect and on-site interaction forC60n−

The lowering of the total energy due to the electron-vibration interaction is calculated for ${\mathit{C}}_{60}^{\mathit{n}\mathrm{-}}$ molecules and the electron-vibration contribution to the on-site interaction is obtained. It is found that ${\mathit{C}}_{60}^{\mathit{n}\mathrm{-}}$ is in the intermediate- to strong-coupling limit, and that the vibration contribution to the on-site interaction if of the order -0.1 to -0.2 eV for n=1 and 3 and of the order +0.3 eV for n=2 and 4.