Development of a many-body Tersoff-type potential for silicon

Abstract

An empirical potential for silicon recently introduced by Tersoff has been found to be unusable for global structural calculations since the bcc structure has lower energy than the diamond structure, by roughly 1 eV/atom, with this potential. Simulated annealing optimization studies of the fitting parameters to the quantum-mechanical data base for silicon reveal that serious structural pathologies (relative to the behavior of silicon) cannot be avoided. We introduce a modification of the Tersoff potential which retains the accurate treatment of surface and defect properties exhibited by that potential but which yields a reasonable fit to the bulk and high-density structural properties of silicon. The resulting potential can be used for global structural calculations.