Clusters and nanoscale materials give rise to properties and behaviour that are governed by size restrictions, and hence display features directly attributable to quantum confinement. Thus they represent ideal media for observing and studying quantum phenomena. This book presents and evaluates some of the latest developments in this area of basic research. Each of the chapters focuses on selected aspects of the field, and the authors endeavour to display the breadth of the subject by presenting some of the important recent advances that have been made through the use of new experimental techniques and theoretical approaches.