The equilibration process for creating heterogeneous (water+gold slab) systems needs more careful considerations as residual stresses are undesirable. A gold slab that spans the simulation box in the x & y directions, and has a thickness of ∼ 24.5Å (6 unit cells of FCC gold with lattice parameter of 4.08Å) is created and equilibrated using anisotropic NPT (pressure control in x, y, and z directions are uncoupled) integration scheme at 1atm and 370K. Subsequently, the simulation box size in the z direction is increased and water molecules are introduced in the empty space created. Gold atoms are removed to carve out nano-grooves in specific cases (see Section III C).