Most textbooks in the field are either too advanced for students or don¿t adequately cover current research topics. Bridging this gap, this classroom-tested book helps advanced undergraduate and graduate students understand electronic structure methods and enables them to use these techniques in their work. The text takes a microscopic view of materials as composed of interacting electrons and nuclei. It explains all the properties of materials in terms of basic quantities of electrons and nuclei, such as electronic charge, mass, and atomic number.