The energetics of steps on transition metal surfaces

We have applied our recently established database of surface free energies and surface free energy anisotropies of low-index surfaces in a study of the energetics of surface steps for cubic transition metals. The first-principles results from the database are used for a cluster expansion of the surface free energy which is subsequently used for high-index surfaces. The accuracy of the expansion is established by a comparison with first-principles results for a few high-index surfaces. Using the cluster expansion for the surface energy of vicinal surfaces we derive the monoatomic step-formation energies for different close-packed bcc and fcc surface facets. Trends in the anisotropy of the step energy are also discussed.