First-principles molecular dynamics simulations of the H2O/Cu(111) interface

A first-principles theoretical study of the water-Cu(111) interface based on density functional calculations is reported. Using differently sized surface models: p(2 x 2), p(4 x 4) and p(4 x 5), we found out that the adsorption energy of a H2O monomer does not significantly change with the surface model though the adsorption geometry is sensitive to the choice of the super-cell surface and, also, to the coverage. Molecular dynamics simulations on the Born-Oppenheimer surface of liquid water on a Cu(111) surface reveal that H2O in the first solvent layer adsorbs O-down and that the H-bond network is weaker upon adsorption on the Cu. Furthermore, absolute electrochemical potentials are presented and compared to the potential of zero charge obtained experimentally and theoretically.