(H2O)(6) on a virtual metal surface: Testing the surface ice rules

The water hexamer has been studied with a classical water-water interaction potential and by quantum calculation at both RHF and MP2 levels. The influ ence of a virtual metal surface on (H2O)(6) has been modeled through geomet ry constraints on the cluster. Additional data on (H2O)(2) and (H2O)(3) are presented to assist the interpretation of the results obtained for the hex amer. These calculations suggest that water molecules in the first layer wi th their hydrogens pointing away from the surface ('flip up') only occur fo r a small range of values of surface lattice constants. In all other cases, the dipole moment of the water molecules is found to lie nearly parallel t o the metal surface.