Crystallography in research and teaching

With the discovery of the periodic arrangement of atoms in crystals by Max von Laue in Munich in 1912, modern crystallography with a structural-atomistic orientation developed. Their results led to serious changes in the “world view” of chemistry, physics, geosciences and materials science. This established crystallography as a fundamental subject for understanding condensed matter.

The most important contributions of crystallography to research in science and technology can be characterized as follows:

  • Symmetry, in particular the theory of space groups, forms the basis for the understanding of crystal structure, phase transformations and domain structures. Symmetries in four and more dimensions describe modulated structures and quasi-crystals.
  • Crystal growth processes are the basis for the investigation and application of crystalline substances and their defects.
  • The systematic analysis of the structure of polycrystalline materials and the resulting knowledge of their material properties are of direct importance for materials science and technical applications.
  • The methods of crystal structure analysis and their constantly growing automation have experienced an unexpected upswing: Today, more than 120,000 crystal structures are known, with growth of about 8% per year.
  • In biology, the structural elucidation of the DNA double helix triggered a stormy development in molecular biology. Furthermore, crystallographic methods allow the determination of complex three-dimensional structures of proteins consisting of thousands of atoms in such detail that statements about their chemical and biological functions are possible.
  • The systematic collection and interpretation of the wealth of crystallographic data, especially in chemistry, mineralogy, biology and materials science, requires the development and use of large databases.
  • A currently very topical research focus is the deviation from the strict grid order: construction errors, order disorder phenomena, pseudosymmetries, modulated structures.
  • The macroscopically anistropic physical properties of crystals are described by tensors and increasingly find an atomistic interpretation. They are essential for understanding the relationships between structure and (technical) properties.
  • In cooperation with scientists from other disciplines, new physical methods and instruments with typical crystallographic objectives are developed. They lead to qualitatively new or quantitatively more extensive results.

Numerous Nobel Prizes for physics, chemistry and medicine were awarded for crystallographically oriented research, starting in 1914 with von Laue and in 1915 with the two Braggs, up to Deisenhofer, Huber and Michel in 1988 for contributions to photosynthesis.

The interdisciplinary embedding of crystallography is also reflected in the teaching of the subject:

  • Students acquire in-depth knowledge in related fields: Primarily material-oriented chemists, mineralogists and biologists are familiarized with physical techniques and measuring methods. Physically oriented students learn “substance-thinking” and are confronted with the variety of complicated structures and symmetries.
  • Intensive handling of practical mathematics, processing large amounts of data, computers and program systems.
  • Overview of all aspects of a solid, from synthesis and cultivation to structure and crystal defects to subtle and technically interesting properties of crystals and multi-crystal systems.
  • For students who specialise in crystallography as a major or minor subject, there are attractive training opportunities and a wide range of career opportunities in industry and research institutes, as the demand for young people with crystallographic training clearly exceeds the supply.

For a long time, crystallography has been firmly established as a core subject in the degree course in mineralogy. At many universities, crystallography is an optional subject in various other diploma courses; at some universities it is already obligatory for materials science. In the Humboldt University of Berlin and in Leipzig, crystallography has its own diploma course of studies.