shown in Figure . The metal-H2O interaction is mediated primarily by 1b1 and 3a1 molecular orbitals, which undergo significant broadening while adsorbed on the surface. The similar energy levels at which the hybridized Pt(d)-3a1 and Pt(d)-1b1 states are distributed for PBE and PBE-D2 methods imply that the different Pt-H2O bonding strength predicted by these methods mainly originate from the differences in the treatment of weak-interactions rather than changes in the electronic structure. It is worth mentioning that apart from the role of solvent, water plays a direct role in ORR being the final product along the 4e -reduction pathway. Therefore, the different strength of binding observed for water monomer here is an immediate indication of varying ORR activity among the other methods when water desorption from the metal surface becomes a kinetically dominating process.