Electron binding energies of linear C3, C5, C7, and C9 clusters

Abstract
Electron propagator calculations are performed on the vertical ionization energies and electron affinities of linear C3, C5, C7, and C9 clusters with a variety of correlation approximations and basis sets. Estimates of adiabatic electron affinities are made as well, and are in excellent agreement with experiment. A bound, excited state of C−9 has been found. Correlation effects are large for the electron affinity calculations and for many vertical ionization energies. The Koopmans description of final states is valid for the Feynman–Dyson amplitudes, but for many cationic states there is considerable shakeup character.