Ab initio and semiempirical calculations have been performed on an (MgO)(16
) cluster model in order to study the effects of water coverage on pure MgO
(100) surfaces. The geometries of various adsorbed water molecules have be
en optimized and the binding energies, charge transfer, and preferential si
tes of interaction analyzed. We have used Mulliken and natural bond populat
ion analysis methods in order to analyze charge distributions and the direc
tion of charge transfer processes. We have also investigated the effects of
low and high coverage on energy gaps, density of states, self-consistent f
ield (SCF) orbital energies, and stretching frequencies. (C) 1999 John Wile
y & Sons, Inc.