This book is the first to describe the chemical aspects of the electronic structures of solids in terms familiar to chemists and materials scientists. The first three chapters give an elementary account suitable for undergraduate students with a grounding in inorganic and physical chemistry; later chapters discuss more advanced aspects, including topics of current research interest such as metal-insulator transitions, low-dimensional solids and "molecular metals," and the properties of surfaces. A wide variety of examples are cited throughout the text to further clarify the discussion for students and for researchers in chemistry, materials science, and solid state electronics.