Book excerpt: Theoretical Aspects of Chemical Reactivity provides a broad overview of recent theoretical and computational advancements in the field of chemical reactivity. Contributions have been made by a number of leaders in the field covering theoretical developments to applications in molecular systems and clusters. With an increase in the use of reactivity descriptors, and fundamental theoretical aspects becoming more challenging, this volume serves as an interesting overview where traditional concepts are revisited and explored from new viewpoints, and new varieties of reactivity descriptors are proposed. Includes applications in the frontiers of reactivity principles, and introduces dynamic and statistical viewpoints to chemical reactivity and challenging traditional concepts such as aromaticity. * Written by specialists in the field of chemical reactivity* An authoritative overview of the research and progress * An essential reference material for students