Incommensurate crystallography / Несоизмеримая кристаллография

Translational symmetry is firmly established as the key property characterizing the crystalline state of matter. This is founded in the successes of translational symmetry in explaining physical properties of crystalline compounds and Bragg reflections in their diffraction patterns, as well as in the many substances that possess periodic atomic structures. An alternative and perhaps better characterization of the crystalline state is by long-range order of the atomic structure. The past fifty years have seen a continuous increase of the awareness that long-range order can be achieved differently than by translational symmetry. Modulated crystals and composite crystals have atomic structures that can be described as variations on periodic structures, while quasicrystals differ from crystals with translational symmetry in a more fundamental way. This book presents the methods of structural analysis of incommensurately modulated crystals and incommensurate composite crystals <...>