Electron-phonon interaction in C70

The matrix elements of the deformation potential of C${}_{70}$ are calculated by means of a simple, yet accurate solution of the electron-phonon coupling problem in fullerenes, based on a parametrization of the ground state electronic density of the system in terms of $s{p}^{2+x}$ hybridized orbitals. The value of the calculated dimensionless total electron-phonon coupling constant is $\lambda \approx 0.1$, an order of magnitude smaller than in C${}_{60}$, consistent with the lack of a superconducting phase transition in C${}_{70}$A${}_3$ fullerite, and in overall agreement with measurements of the broadening of Raman peaks in C${}_{70}$K${}_4$. We also calculate the photoemission cross section of C${}_{70}^{-}$, which is found to display less structure than that associated with C${}_{60}^{-}$, in overall agreement with the experimental findings.