Interface water cluster anions (H2O)(n)(-) (n less than or equal to 12) com
posed of two to four fragments are simulated in the unrestricted Hartree-Fo
ck approximation with the second order Moeller-Plesset perturbation theory
corrections taken into account with the 6-31++G(**) basis set either augmen
ted or not with the floating center of eight s functions. A linear dependen
ce of the circumsphere radius involving central molecules of the anions on
1/n provides an estimate of the excess electron radius in condensed water (
about 2.5 Angstrom). Vertical detachment energies, approximated with linear
dependences on n(-1/3) are extrapolated to the values around 3.4 eV for bu
lk water. (C) 2001 Elsevier Science B.V. All rights reserved.