Electron propagator calculations on the ground and excited states of C60(-).

Electron propagator calculations in two approximations—the third-order algebraic, diagrammatic construction and the outer valence Green’s function (OVGF)—have been performed on the vertical electron affinities of C60 and the vertical electron detachment energies of several states of C60(–) with a variety of basis sets. These calculations predict bound (2)T1u and (2)T1g anions, but fail to produce (2)T2u or (2)Hg anionic states that are more stable than ground-state C60. The electron affinity for the (2)Ag state is close to zero, but no definitive result on its sign has been obtained. This state may be a resonance or marginally bound anion. The OVGF prediction for the vertical electron detachment energy of (2)T1u C60(–), 2.63 eV, is in excellent agreement with recent anion photoelectron spectra.