Development of a First-Principles Many-Body Potential for Beryllium

An interatomic potential is developed for beryllium based on the simultaneous fit to the total energy of 2- to 5-atom clusters obtained in the local-spin-density approximation. The increasing $s-p$ hybridization with cluster size is incorporated through a three-body term depending on the number of atoms. Results using the potential give an excellent description of the early stages of crystal growth and a correct prediction of the stability of the hcp lattice over bcc and fcc phases.