The orientation of the interfacial water molecules is influenced by the chemical interactions between platinum and water, the free charge density (affecting the direction of the water dipoles) as well as the presence of adsorbates (through blocking of sites and manipulating the electrostatic effect of the free charge density). Here, three main configurations of interfacial water can be distinguished: H 2 O-parallel, with the molecule adsorbed via the oxygen atom on a top-site of the Pt surface and both hydrogen atoms slightly tilted away from the surface. H-up, where one hydrogen atom points away from the surface and H-down with one hydrogen atom directed towards the surface, see Fig. for visualization. Numerous studies have contributed here, obtaining small to negligible differences in stability between the two orientations. In the following, we focus on -with no claim to completeness -experimental and theoretical work including the electrode potential into their investigation of the Pt|H 2 O interface. In our ReaxFF-MD study, we observe a change of the preferred orientation of interfacial H 2 O from H-up to H-down with increasing electrode potential.