Book excerpt: A molecular understanding of electron transfer is crucial to understanding the molecular basis of metabolic processes in which electron transfer is essential, diseases involving these processes, and drug design targeting these processes. This book provides a cohesive and comprehensive discussion of computational methods used for electron transfer proteins and what has been learned from such studies for the first time in a book. It also gives an overview of results from theory, computation, and experiment about electron transfer proteins. This resource also includes strategies for studying metal sites that have not been examined computationally.