Application of the Gutzwiller method to neutral and ionic C60 aggregates.

Abstract

We use the Gutzwiller method for studying various characteristic energies of ${\mathrm{C}}_{60}$ in the free state (first and second ionization energy, electron affinity, and singlet and triplet excitation energies). We improve a previous description by adding a term that takes into account the noncompensation of the overall nuclear and electronic charges in ionic species. Our results are in good agreement with experiment. We also study ${\mathrm{C}}_{60}^{2\mathrm{\ensuremath{-}}}$ and ${\mathrm{C}}_{60}^{3\mathrm{\ensuremath{-}}}$, which are nonstable in the free state but can be produced in solution. By including a polarization term and by using the electron affinities calculated in the free state, we evaluate the reduction potentials in solution for the reactions ${\mathrm{C}}_{60}^{\mathit{Z}\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}${\mathrm{C}}_{60}^{(\mathit{Z}+1)\mathrm{\ensuremath{-}}}$ (Z=0,1,2) and compare them with recent experimental data.