About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Paper
Electronic structure of hydrogen-bonded H2O
Abstract
We have studied the electronic structure of H2O adsorbed on different metal surfaces between 7 and 200 K using photoelectron spectroscopy. From the valence-orbital spectra we are able to distinguish three different phases of adsorbed H2O: (a) single-adsorbed H2O molecules at temperatures close to the desorption point, (b) partially hydrogen-bonded H2O clusters for coverages of a monolayer or less, and (c) fully hydrogen-bonded ice at low temperatures and several monolayers of coverage. For phase (a), we find valence molecular orbitals which are almost rigidly shifted upwards relative to the gas phase by a final-state relaxation shift of 1.3 eV. All orbitals are broadened by 1.0-1.5 eV relative to the gas phase. For phase (b), we identify two inequivalent types of H2O molecules whose orbital energies differ by 1.5-2 eV. This splitting is identical to the electrostatic shift of molecular-orbital energies as calculated for the hydrogen-bonded H2O dimer by Umeyama and Morokuma. In this model the set of molecular orbitals with higher binding energy is assigned to the hydrogen-acceptor molecule and the set with lower binding energy to the hydrogen-donor molecule. At monolayer coverage we find about twice as many donors as acceptors. © 1983 The American Physical Society.