(a) Energy per unit area, γ-potential (d₀=2.171 Å), as a function of the relative slip sxr and the change in interfacial spacing uyr in the case of δ_x=0.6503 and δ_y=-4.5414. (b) γ-potential as a function of sxrforuyr=0 . (c) γ-potential as a function of the change in interfacial spacing uyr . The solid curves are given by Eq. (22) and the discrete points are the results of a first-principles calculation.