On the other hand, (2×2) supercells were employed for fcc (001) and (011) surfaces, bcc (011) surface, and hcp (0001) and (112 ̅ 0) surfaces, see Fig. , having eight atoms per layer. Thus, the resulting coverage of all the surfaces resulted in similar 1 /8 or 1 /9 of a monolayer (ML), depending on the number of metallic atoms forming each layer.