Between vapor and ice: Free water clusters studied by core level spectroscopy

Abstract

Core level x-ray absorption and photoemission spectra of free water clusters are presented. Core and valence photoemission spectra show a weak but gradual change with cluster size. Comparisons to spectra of the isolated molecule and solid ice indicate that water molecules have a lower average coordination in clusters than in the bulk solid. X-ray absorption spectra reveal spectral characteristics between the free molecule and the bulk. These are compared to similar spectra of the isolated molecule and solid ice, and discussed in connection to calculated structures.