We have investigated the relative stability between H-up and H-down configurations for all the methods, and the results are represented in Figure . It can be seen that except rPW86, all other methods show higher stability for H-down configurations. Different initial geometries were chosen for the water bilayers and selected the stable configurations for further calculations. The adsorbed water bilayer differs between functionals in terms of the spatial distribution of water molecules within the hexagonal bilayer (Figure ). The difference in the extent of interactions of water bilayers is quantified in terms of mean absolute deviation in their bond lengths to the surface and the change in the work function of the surface when water bilayers are included, which are given in Figure . On the contrary to the similar configuration observed for water monomer adsorption, the water molecules within the bilayers are in perfect bilayer arrangement from the surface only for RPBE-D3 H-down and rPW86 H-up configurations. This can be understood from the highest average Pt-H2O bond lengths for the BLs in these methods, allowing the inter-molecular interactions to result in a nearly perfect buckled hexagonal network. Nonetheless, the hydrogenbonded network is identified to be retained for all the methods. To understand the stability variation of bilayers over the Pt(111) surface, the average adsorption energies of the water bilayers are calculated as,