The first three articles of the new `Best practice in crystallography' series have been published covering a guide to growing crystals for single-crystal diffraction studies, a guide to performing photocrystallography and a review detailing what aspects of crystal structure are of particular importance to determining electrical conductance in organic materials.

A catalog of techniques, tips, tricks, and encouragement for growing crystals suitable for X-ray crystallography.

Over the last three decades, the technology that makes it possible to follow chemical processes in the solid state in real time has grown enormously. These studies have important implications for the design of new functional materials for applications in optoelectronics and sensors. Light–matter inter­actions are of particular importance, and photocrystallography has proved to be an important tool for studying these inter­actions.

Knowledge of the mol­ecular packing within the crystal structures of organic semi­con­duc­tors has been instrumental in understanding their solid-state electronic properties. Crystal structures are thus becoming increasingly important for enabling engineering properties, understanding poly­mor­phism in bulk and in thin films, exploring dynamics and elucidating phase-transition mech­a­nisms.

The article of Sommer [Acta Cryst. (2024), C80, 337–342] provides a concise and effective introduction to the subject of growing crystals suitable for structure determination.

To broaden the community and encourage researchers to use photocrystallographic methods, review articles, such as that of Hatcher et al. [(2024). Acta Cryst. C80, 585–600], showing the fundamentals of the approaches, most significant examples of such studies, but also guiding the reader through various stages of sample preparation and experiment planning, are very much needed.

In their contribution to the `Best practice in crystallography' series, Schweicher et al. [(2024). Acta Cryst. C80, 601–611] present a compelling overview, describing the importance and influence of mol­ecular structure, crystal packing and crystal lattice dynamics on both theoretical and experimental charge transport behaviour in crystalline environments.