FIRST-PRINCIPLES DETERMINATION OF EQUILIBRIUM CRYSTAL SHAPES FOR METALS AT T=0

We propose a simple method to evaluate the energies of ideal metal sur faces as a function of orientation based on cluster energy expansion. By symmetry only clusters with even-number corners will be present. It is found that the energy expansion converges rapidly and in most case s can be truncated at the pair interaction level. The parameters can b e determined from a limited number of low-index surface energies obtai ned from first-principles calculations. The equilibrium crystal shape at T = O is then predicted and the step energy on major facets is deri ved for some fee metals.