Minimizing atomic configurations of short range pair potentials in two dimensions: crystallization in the Wulff shape

We investigate ground state configurations of atomic systems in two dimensions as the number of atoms tends to infinity for suitable pair interaction models. Suitably rescaled, these configurations are shown to crystallize on a triangular lattice and to converge to a macroscopic Wulff shape which is obtained from an anisotropic surface energy induced by the microscopic atomic lattice. Moreover, sharp estimates on the microscopic fluctuations about the limiting Wullf shape are obtained.