Recent developments in the structural science of materials

This Editorial surveys the current status and recent developments in the structural science of materials as exemplified by the articles recently published in IUCrJ.

Integral membrane proteins and free electron lasers – a compatible couple indeed!

Several structures of membrane transport proteins in complex with mechanistically-relevant ligands, determined by serial femtosecond crystallography of microcrystals at an X-ray free-electron source source, are presented. These results, including investigation of approaches to data quality assessment and refinement from low-redundancy data, indicate the feasibility of using this approach for ligand screening.

Modularity and three-dimensional isostructurality of novel synthons in sulfonamide–lactam cocrystals

Novel supramolecular synthons for primary sulfonamides with cyclic amides (GRAS coformers) are introduced for the crystal engineering of pharmaceutical cocrystals of sulfa drugs. The cocrystals of this model study exhibit isostructurality and isosynthons mediated by SO₂NH₂⋯CONH hydrogen bonding.

Combinatorial selection of molecular conformations and supramolecular synthons in quercetin cocrystal landscapes: a route to ternary solids

Crucial `purification' steps inherent to the `selection' of particular molecular conformations and supramolecular synthons in solution leads to a successful synthetic strategy for ternary solids, a normally difficult exercise in crystal engineering. This work also suggests a parallel between such strategies and combinatorial chemistry.

Structural studies of P-type ATPase–ligand complexes using an X-ray free-electron laser

The structure determination of P-type ATPase–ligand complexes from microcrystals by serial femtosecond crystallography using a free-electron laser is described. The feasibility of the method for ligand screening is demonstrated, and SFX data quality metrics as well as suitable refinement procedures are discussed.

A novel inert crystal delivery medium for serial femtosecond crystallography

Viscous sample delivery that decreases the net protein consumed in serial femtosecond crystallography is described. The agarose stream has a low background, is compatible with membrane proteins and can be used at a wide range of temperatures.

Native SAD is maturing

Advancements in source stability, X-ray optics, detectors, goniometry, data-collection strategies and data reduction and phasing software made over the past decade have placed native SAD at the verge of becoming a `first-choice' method for both de novo and molecular-replacement structure determination.

Modelling the experimental electron density: only the synergy of various approaches can tackle the new challenges

The most recent research in charge spin and momentum density is presented and discussed.

Application of synchrotron through-the-substrate microdiffraction to crystals in polished thin sections

The synchrotron through-the-substrate X-ray microdiffraction technique is applied to the structural study of microvolumes of randomly oriented crystals embedded in polished thin sections. The whole procedure is discussed in detail with the help of examples from petrology, and possible future developments are envisaged.

Sub-atomic resolution X-ray crystallography and neutron crystallography: promise, challenges and potential

Neutron crystallography and sub-atomic X-ray crystallography complement each other in defining hydrogen positions in macromolecules. Significant advances have been made but much effort is still required if neutron crystallography is to become a mainstream activity.