An application of SIEST-A-RT was presented that combined the activation relaxation technique, ART nouveau, and the local-basis ab initio code SIESTA, to study self-defect migration pathways in semiconductors. SIESTA provides reliable descriptions of defect properties in semiconductors directly comparable to experiment as well as, once combined with ART nouveau, a detailed description of their possible migration mechanisms. This package was used to characterize the properties of vacancies in Si and GaAs, such as relaxation geometries, formation energies at low and high temperature, diffusion mechanisms and migration barriers. It was shown here that diffusion in bulk semiconductors was a rich and complex phenomenon that depends not only on the geometry of the defect and the surrounding lattice but also on its charge.

Ab initio Simulations of Self-Diffusion Mechanisms in Semiconductors. F.El-Mellouhi, N.Mousseau: Physica B, 2007, 401-402, 658-61