Interaction between graphene and nickel(1 1 1) surfaces with commensurate and incommensurate orientational relationships

The interaction energy between a rigid defect-free graphene sheet and a fixed Ni(1 1 1) surface with respect to rotational and translational displacements is examined using an empirical bond order potential. The Rosei (hollow site) structure, and others in which metal atoms are adjacent to hollow sites in graphene, give rise to global and local energy minima, respectively, whereas the interaction energy is almost constant for incommensurate structures. Only a few degrees rotation from the Rosei structure substantially diminishes the energy barrier for translational displacement.