Recent developments in many-body perturbation theory calculations were reviewed which had permitted the study of interfaces and defects. Starting from the theoretical basis of many-body perturbation theory, Hedin's equations were presented, leading to the GW and GWΓ approximations. A perturbative approach, which was the most commonly used one for obtaining quasiparticle energies, was introduced. The practical strategy presented for dealing with the frequency dependence of the self-energy operator was based upon either plasmon-pole models or the contour deformation technique; with the latter being the more accurate. Also considered was the extrapolar method for reducing the number of unoccupied states which needed to be included explicitly in the calculations. The use of the PAW method in the framework of many-body perturbation theory was also described. Finally, results which were obtained using many-body perturbation theory for band offsets at interfaces and for defects were presented, with the emphasis being placed on the main difficulties and caveats.

Electronic Properties of Interfaces and Defects from Many-Body Perturbation Theory: Recent Developments and Applications. M.Giantomassi, M.Stankovski, R.Shaltaf, M.Grüning, F.Bruneval, P.Rinke, G.M.Rignanese: Physica Status Solidi B, 2011, 248[2], 275–89