Modularity and Twinning in Mineral Crystal Structures

<p>The articles published in this Special Issue reprint offer a sound update of research fields</p><p>where the concepts of modular crystallography are important and provide unique keys to</p><p>understand and to solve problems of structural crystallography. Polytypism</p><p>polysomatism and twinning are fertile fields of research and their basic principles-</p><p>oen coupled with the OD (order-disorder) theory-are powerful tools to solve and</p><p>classify related crystal structures. Research on twinning and its consequences on</p><p>structure and properties of crystalline materials is cutting-edge e.g. dealing with</p><p>relations between twin walls and piezoelectricity.</p>