The adsorption of water on a fully hydroxylated silica surface is studied by using density-functional total-energy and molecular dynamics calculations. The (100) surface of $\beta (\alpha )$-cristobalite covered by geminal hydroxyls has been taken as the substrate. A well-ordered and stable two-dimensional ice with quadrangular and octagonal patterns of hydrogen bond (H-bond) networks—an ice tessellation—is found on the surface for the first time. With the vibrational recognition, the four water molecules in the quadrangle are found to be bonded by strong H bonds while the quadrangles are connected to each other by weak H bonds. This configuration is the most stable, because all the water molecules are fully saturated with H bonds either to each other or to the surface hydroxyl groups.

• Received 27 November 2003

DOI:https://doi.org/10.1103/PhysRevLett.92.146102