Electron binding energies of water clusters: Implications for the electronic properties of liquid water

Green's function (GF) calculations for the valence electron binding energies of water clusters (H2O)(2-8) are reported. The results are compared with experiment for H2O and (H2O)(2), and with Hartree-Fock and Kohn-Sham calculations with an exchange-correlation functional parametrized to reproduce electronic properties of the dimer. For the liquid, sequential Monte Carlo/GF calculations lead to estimates of the outermost electron binding energy (11.59 +/- 0.12eV) and of the water conduction band edge (V-0) as -0.79 +/- 0.08 eV. Our predictions agree with experimental and recent theoretical results and support that the water electron affinity (-V-0) is smaller than the typical literature value (1.2 eV). (c) 2006 Elsevier B.V. All rights reserved.