Crystallography and Crystal Defects Revised Edition A. Kelly, Churchill College, Cambridge, UK G. W. Groves, Exeter College, Oxford, UK and P. Kidd, Queen Mary and Westfield College, University of London, UK The concepts of crystallography are introduced here in such a way that the physical properties of crystals, including their mechanical behaviour, can be better understood and quantified. A unique approach to the treatment of crystals and their defects is taken in that the often separate disciplines of crystallography, tensor analysis, elasticity and dislocation theory are combined in such a way as to equip materials scientists with knowledge of all the basic principles required to interpret data from their experiments. This is a revised and updated version of the widely acclaimed book by Kelly and Groves that was first published nearly thirty years ago. The material remains timely and relevant and the first edition still holds an unrivalled position at the core of the teaching of crystallography and crystal defects today. Undergraduate readers will acquire a rigorous grounding, from first principles, in the crystal classes and the concept of a lattice and its defects and their descriptions using vectors. Researchers will find here all the theorems of crystal structure upon which to base their work and the equations necessary for calculating interplanar spacings, transformation of indices and manipulations involving the stereographic projection and transformations of tensors and matrices.