In recent years, researchers have increasingly recognized the dominant role of the local atomic environment in controlling the electronic structure and properties of materials. This recognition has spawned the "real-space" approach that provides a coherent framework for the study of perfect and defective crystals and non-crystalline materials. In addition to presenting these ideas, this text details the reciprocal-space approach--exemplified in band theory--and draws powerful links between the two approaches. The book includes illustrations and examples of many up-to-date calculations based...