Combining X-rays, neutrons and electrons, and NMR, for precision and accuracy in structure–function studies

The distinctive features of the probes used in understanding the structure of matter focusing on biological sciences, but not exclusively, are described in the modern context to minimize the consequences of artefactual information in data interpretation. The precision and accuracy of both data and technique are revisited. A variety of structural results are described that reach beyond reductionism to the whole biological organism. All these aspects open new doors to change and extend the foundations of the structural sciences.

New perspectives in macromolecular powder diffraction using single-photon-counting strip detectors: high-resolution structure of the pharmaceutical peptide octreotide

The complete structure of a pharmaceutical molecule, octreotide (PDB code 6vc1), obtained by X-ray powder diffraction data at 1.87 Å resolution, using a MYTHEN II detector system at the Swiss Light Source, is reported.

A new electron diffraction approach for structure refinement applied to Ca₃Mn₂O₇

The `digital' large-angle convergent-beam electron diffraction (D-LACBED) method uses computer control of a transmission electron microscope to collect hundreds of diffraction patterns from a region a few nanometres in size, which are combined into a single data set. The sensitivity of the resulting patterns to crystal structure is explored using the Ruddlesden–Popper oxide Ca₃Mn₂O₇ and it is found that refinement of atomic coordinates can be performed to sub-picometre precision.

Symmetry relations in wurtzite nitrides and oxide nitrides and the curious case of Pmc2₁

Binary and multinary nitrides in a wurtzitic arrangement are very interesting semiconductor materials. The group–subgroup relationship between the different structural types is established.

A discussion on `Domain formation and phase transitions in the wurtzite-based heterovalent ternaries: a Landau theory analysis'

A scientific exchange on an earlier paper [Quayle (2020). Acta Cryst. A76, 410–420] has led to the clarification of some of the points.

Bloch-wave interpretations of Gjønnes–Moodie lines in convergent-beam electron diffraction for non-symmorphic space-group crystals

The dynamical effect in high-energy electron diffraction in non-symmorphic space-group crystals is discussed using Bloch waves. A contrast mechanism for Gjønnes–Moodie lines by Bloch waves is described.

Diffraction line profiles from polydisperse crystalline systems. Corrigenda

Errors in the article by Scardi & Leoni [(2001), Acta Cryst. A57, 604–613] are corrected.

Electrons in Solids. Mesoscopics, Photonics, Quantum Computing, Correlations, Topology

Introduction to Crystallography