Molecular reorientation of water adsorbed on charged Ag(1 1 1) surfaces

In this work we present first principles calculations of water adsorption over charged Ag(1 1 1) surfaces. The orientation of the adsorbed water molecule with respect to the surface changes from oxygen pointing away from the surface at negative charges to oxygen pointing towards the surface at positive charges. At zero charge the water molecule is oriented approximately parallel to the surface plane. Complete orientation of the molecule in the direction of the field is achieved for a critical charge density of 15 μC cm−2 for both positive and negative charges.