Which electronic structure method for the study of defects: A commentary



A historic perspective is provided to the choice of methodologies for point defects in semiconductors. A summary and commentary on the highlights of the CECAM workshop: “Which electronic structure method for the study of defects?” is given, attempting to provide a link between the different contributions. To this purpose different themes running through the compilation are identified and rather than discussing individual contributions one by one, the discussion is focused around these themes. The first theme is the problem of correcting for finite size effects. The second theme is the problem of the underestimate of the band gaps and how to correct for it in defect calculations. The third theme is the self-interaction error of local density approximation (LDA) and its repercussions for polaronic defects. The fourth theme is progress in methods beyond LDA that are becoming applicable to point defects, either for ground states or excited state properties.