This book describes the process of application of neutron diffraction, which involves determining the atomic/magnetic structure of a material using neutron scattering. The technique of neutron diffraction has found extensive applications in the study of crystals, magnetic composition and inner stress of crystalline materials of diverse categories, including nanocrystals. This book contains important data on the current status of neutron diffraction studies of crystals for experts keen on researching crystals and monitored control of their service traits, because their physical and mechanical properties are largely results of their crystal structure. Topics covered in this book have been dealt with meticulously and this book will be important to scientists keen on exploring the possibilities of this process. This text will further assist the studies of crystalline, magnetic & macrostructures of usual crystal materials and nanocrystals to achieve a new benchmark and propagate the creation of new resources with enhanced service traits and development of pioneering ideas.