Density-functional theory

Density-functional theory (DFT) has become the major workhorse of modern computational chemistry and materials science thanks to tremendous progress in methodological developments, efficient implementations of DFT codes, and high-performance computational facilities in the past three decades. This chapter aims at providing a short overview on various aspects of DFT, including its theoretical foundations, a large variety of density-functional approximations with different sophistication, and key ingredients of practical implementations of DFT. We also present a few case studies that illustrate key issues that are relevant for practical applications of DFT for real chemical problems.