This book investigates the possible ways of improvement by applying more sophisticated electronic structure methods as well as corrections and alternatives to the supercell model. In particular, the merits of hybrid and screened functionals, as well as of the +U methods are assessed in comparison to various perturbative and Quantum Monte Carlo many body theories. The inclusion of excitonic effects is also discussed by way of solving the Bethe-Salpeter equation or by using time-dependent DFT, based on GW or hybrid functional calculations. Particular attention is paid to overcome the side effects connected to finite size modeling. The editors are well known authorities in this field, and very knowledgeable of past developments as well as current advances. In turn, they have selected respected scientists as chapter authors to provide an expert view of the latest advances. The result is a clear overview of the connections and boundaries between these methods, as well as the broad criteria determining the choice between them for a given problem. Readers will find various correction schemes for the supercell model, a description of alternatives by applying embedding techniques, as well as algorithmic improvements allowing the treatment of an ever larger number of atoms at a high level of sophistication.

Chris G. Van de Walle is Professor at the Materials Department of the University of California in Santa Barbara. Before that he worked at IBM Yorktown Heights, at the Philips Laboratories in New York, as Adjunct Professor at Columbia University, and at the Xerox Palo Alto Research Center. Dr. Van de Walle has published over 200 articles and holds 18 U.S. patents. In 2002, he was awarded the David Adler Award by the APS. Dr. Van de Walle's research focuses on computational physics, defects and impurities in solids, novel electronic materials and device simulations. Jörg Neugebauer is the Director of the Computational Materials Design Department at the Max-Planck-Institute for Iron Research in Düsseldorf, Germany. Since 2003 he has been the Chair of Theoretical Physics at the University of Paderborn.Before that, he held positions as Honorary Professor and Director of the advanced study group 'Modeling' at the Interdisciplinary Center for Advanced Materials Simulation (ICAMS) at the Ruhr University in Bochum, Germany. His research interests cover surface and defect physics, ab initio scale-bridging computer simulations, ab initio based thermodynamics and kinetics, and the theoretical study of epitaxy, solidification, and microstructures. Alfredo Pasquarello is Professor of Theoretical Condensed Matter Physics and Chair of Atomic Scale Simulation at EPFL, Switzerland. His research activities focus on the study of atomic-scale phenomena with the aim to provide a realistic description of the mechanisms occurring on the atomic and nanometer scale. Specific research projects concern the study of disordered materials and oxide-semiconductor interfaces, which currently find applications in glass manufacturing and in the microelectronic technology, respectively. Peter Deák was Professor and Head of the Surface Physics Laboratory at the Budapest University of Technology & Economics and is currently Group Leader at the Center for Computational Materials Science in Bremen, Germany. His research interests cover materials science and the technology of electronic and electric devices, functional coatings and plasma discharges, and atomic scale simulation of electronic materials. Peter Deák has published over 150 papers, eight book chapters, and six textbooks. Audrius Alkauskas holds a position at the Electron Spectrometry and Microscopy Laboratory of the EPFL, Switzerland. His scientific interests cover computational material science, theoretical solid state spectroscopy and surface and interface science with respect to applications in renewable energy, photovoltaics, energy conversion, and molecular nanotechnology.

1. Advances in Electronic Structure Methods for Defects and Impurities in Solids 2. Accuracy of Quantum Monte Carlo Methods for Point Defects in Solids 3. Electronic Properties of Interfaces and Defects from Many-body Perturbation Theory: Recent Developments and Applications 4. Accelerating GW Calculations with Optimal Polarizability Basis 5. Calculation of Semiconductor Band Structures and Defects by the Screened Exchange Density Functional 6. Accurate Treatment of Solids with the HSE Screened Hybrid 7. Defect Levels Through Hybrid Density Functionals: Insights and Applications 8. Accurate Gap Levels and their Role in the Reliability of Other Calculated Defect Properties 9. LDA+U and Hybrid Functional Calculationsfor Defects in ZnO, SnO2 and TiO2 10. Critical Evaluation of the LDA+U Approach for Band Gap Corrections in Point Defect Calculations: The Oxygen Vacancy in ZnO Case Study 11. Predicting Polaronic Defect States by Means of Generalized Koopmans Density Functional Calculations 12. SiO2 in Density Functional Theory and Beyond 13. Overcoming Bipolar Doping Difficulty in Wide Gap Semiconductors 14. Electrostatic Interactions between Charged Defects in Supercells 15. Formation Energies of Point Defects at Finite Temperatures 16. Accurate Kohn-Sham DFT with the Speed of Tight Binding: Current Techniques and Future Directions in Materials Modelling 17. Ab Initio Green''s Function Calculation of Hyperfine Interactions for Shallow Defects in Semiconductors 18. Time-Dependent Density Functional Study of the Excitation Spectrum of Point Defects in Semiconductors 19. Which Electronic Structure Method for the Study of Defects: A Commentary