A novel and efficient simulation method was developed for the determination of the saddle-point configuration of a localized structural defect in a crystalline lattice. It was used to determine the predominant mechanisms of dislocation and self-interstitial mobility, and of dislocation intersection. The method was capable of identifying the migration path between 2 prescribed defect configurations, and involved sampling a discretized path which connected 2 neighboring potential energy minima. By using the Stillinger-Weber interatomic potential for Si, activation energies were found for the displacement of the 30° partial dislocation (glide set) via a double-kink mechanism, and for the migration of a self-interstitial via a jump-rotation process. Jog and kink formation were observed at the intersections of straight partial dislocations, and the effects of strong core reconstruction upon the energetics of intersection were considered.

V.Bulatov, M.Nastar, J.Justo, S.Yip: Nuclear Instruments and Methods in Physics Research B, 1997, 121[1-4], 251-6