@TechReport{ Griebel.Jager.Voigt:2004b, institution = {Institute for Numerical Simulation, University of Bonn}, author = {M. Griebel and L. Jager and A. Voigt}, title = {Computing Diffusion Coefficients of Intrinsic Point Defects by Atomistic Simulations}, year = {2005}, annote = {report,C5}, pdf = {http://wissrech.ins.uni-bonn.de/research/pub/jager/comp_diff.pdf} , ps = {http://wissrech.ins.uni-bonn.de/research/pub/jager/comp_diff.ps} , abstract = {We present a new method to identify and track intrinsic point defects in a silicon crystal in a molecular dynamics simulation. If the canonical ensemble is employed, the resulting trajectory can be used to compute the diffusion coefficients of defects for a prescribed temperature. A fit of these values for different temperatures to an Arrhenius--type function gives the temperature dependence of the diffusion coefficient over the whole range of interest. For this purpose, we performed simulations employing the Stillinger--Weber potential as well as the Tersoff potential. We were able to improve the accuracy of the approximation of the diffusion coefficients for self-interstitials and vacancies computed by Sinno (1998) and Tang et al. (1997).} }