Adsorption of water on MgO(100): A singular behavior

Interaction-potential minimization and molecular-dynamics simulations show that a perfect MgO(100) surface accomodates very stable flat water monolayers differing only by the mutual orientations of the molecules above the cations, without evidence for significant hydrogen bonding with the substrate and between the ${\mathrm{H}}_2\mathrm{O}$ molecules. Increasing coverage leads to the occurrence of an upper solid versus liquidlike structure not hydrogen bonded to the stable monolayer, which tends to tear up at 300 K. These results are in good agreement with recent experimental data.