AXIS (AI-based Crystal Identification System) combines artificial intelligence with an iterative Lab-in-the-Loop approach for automated crystal detection. AXIS ensures high performance in crystal detection, requires small training datasets and facilitates rapid adaptation to local and changing conditions at any given facility.

We demonstrate a grazing-incidence XFEL platform that simultaneously records time-resolved GISAXS and GID, enabling depth-selective probing of ultrafast surface and subsurface dynamics in a laser-irradiated gold film. The approach correlates nanoscale morphology evolution with lattice compression, melting and recrystallization, providing benchmarks for ultrafast laser–matter interaction models.

Kinetic effects can be a critical factor in the study of high-pressure phase transitions. X-ray diffraction experiments on the timescales of the laboratory and the synchrotron can provide complementary results on such transformations.

The paper by Gilski et al. in this issue [IUCrJ (2026), 13, 132–145] focuses on the stereochemical analysis of the catalytic mechanism of asparaginases with the aim of resolving key ambiguities in the mechanism. These enzymes have found truly remarkable therapeutic success in the treatment of childhood leukemias.

This blind test uses three known samples to determine the accuracy limits of 3D electron diffraction and to assess various challenges. The study aims to evaluate how well different users with diverse experimental setups can perform tasks such as hydrogen-atom detection, mixed occupancy analysis and absolute structure determination. By comparing results across multiple participants and platforms, we can gauge the reliability of the method and identify potential areas for improvement in 3D electron diffraction techniques.

Modelling of radiation damage and beam-induced heating at extremely high flux macromolecular crystallography beamlines is presented.

Differential scanning fluorimetry (DSF) assesses protein thermal stability in solution using a standard real-time PCR instrument. Optimizing the protein buffer composition and crystallization conditions through DSF can significantly enhance crystal quality.

An automated, low-volume microbatch-under-oil crystallization approach is described that rapidly maps phase diagram boundaries. This approach rationalizes the production of microcrystal suspensions for serial crystallography by explicitly distinguishing metastable from nucleation zones, thereby replacing empirical trial and error with a quantitative guide to sample optimization.

Commensurately and incommensurately modulated phases of chlorpropamide have been obtained for the first time on hydro­static compression of its δ polymorph.

Stereochemical analysis based on the principle of structure correlations has been carried out to identify the primary nucleophile residue in each of the three classes of l-asparaginases and in a group of classless enzymes, helping to confirm their classification.

A user-friendly interface has been developed for XDS, enabling efficient real-time and batch processing of 3D ED data to accelerate structure determination.

Phase transitions in metastable rutile-related V0.92O2 were studied with single-crystal X-ray diffraction and measurements of electronic transport properties at extreme conditions. The high-tem­per­a­ture incommensurate phase was found to be insulating.

A pipeline with a graphical user interface for real-time and offline 3D ED/microED data processing by XDS was developed. The pipeline aims to improve efficiency, minimize redundant data processing work and provide users with real-time feedback during data collection.

The crystal structure and thermal expansion behaviour of di­acet­y­lene were determined via diffraction methods and supplemented by spectroscopic techniques. The similarities to the structure of acetylene and implications for Titan in situ exploration are discussed.

A generalized diffraction model is presented for anisotropic nanomaterials with fibre symmetry, enabling the extraction of 3D orientation, strain and angular dispersion from wide-angle X-ray scattering patterns without sample rotation. Validated on chitinous Bouligand structures in shrimp cuticle, this framework allows robust multi-reflection analysis and is broadly applicable to complex biological and synthetic fibre-based materials.

The Ewald sphere is inherent in image formation in the electron microscope and must therefore be part of the reconstruction of cryoEM maps. This study examines linear image-formation theory to show how Ewald sphere information derives from focal series micrographs and relates to the exit wave. It concludes by suggesting the proper way to correct for the contrast transfer function for cryoEM reconstruction.

Linear-scaling fragment Hirshfeld atom refinement has been implemented in Olex2 within the NoSpherA2 interface, which also solved previous issues with hydrogen bonds. This allowed the refinement of two small proteins, crambin and rubredoxin (the latter including a metal site), with quantum mechanical aspherical atomic form factors.

A stepwise guide to the crystallization of charged molecules from aqueous solutions is presented.

Bacteriophage ΦKZ is a massive bacterial virus with potential as a therapy for Pseudomonas aeruginosa, which forms a bacteriophage nucleus in infected cells to exclude the host immune system, and transcribes its genes with its own, non-canonical multi-subunit RNA polymerase. The structure of this polymerase in the process of binding an analogue of its cognate promoter is resolved, revealing an unanticipated method of promoter consensus recognition involving the β-like, rather than the σ-factor-like subunit.

This study presents the crystal structure of human rhinovirus (hRV)-B14 3C protease bound to AG7404, a broad-spectrum antiviral inhibitor, at a resolution of 2.11 Å. Antiviral assays and in silico studies provide structural insights into AG7404's efficacy and binding mechanism against hRV-B14, hRV-A16 and hRV-A21 3C proteases.

An advanced X-ray ptychography system has been developed that facilitates nanoscale imaging across both tender and hard X-ray regions using a single optical setup.

The development of methods for low-cost time-resolved cryo-EM using an on-grid mixing strategy is described.

Electrostatic potential maps of proteins are calculated at various resolutions using the transferable aspherical atom model (TAAM) to determine the relations between the electrostatic potential and resolution for different atom types.

The influence of the X-ray step size on radiation damage occurring in serial data collection from a metalloprotein using sheet-on-sheet fixed-target chips was investigated at fourth-generation synchrotron and XFEL beamlines.

The room-temperature structure of Sr2FeIrO6, a double perovskite with notable magnetic and structural properties, has been debated extensively. Our high-resolution and high-pressure synchrotron-based powder X-ray diffraction findings provide compelling evidence to reconcile these divergent positions, laying groundwork for future research.

Thortveitite-related Fe2P2O7 shows three reversible phase transitions and has an incommensurately modulated crystal structure at room temperature.

Seven venetoclax solvates were structurally characterized and studied for their desolvation behaviour, leading to the identification of two solvent-free polymorphs. Advanced crystallographic and computational analyses, including Solvate Analyser, CSD-Particle, FTIR and solid-state NMR, revealed key factors governing solvate stability and transformation. Notably, the acetone solvate exhibited exceptional stability and the desolvated forms retained the molecular arrangement of their parent solvates.

Structural analysis of the co-crystal between human DNA glycosylase hOGG1 and a light-sensitive substrate analog highlights its utility as a platform for real-time observation of catalytic dynamics.

We demonstrate the application of a nitric oxide releasing photocage system for time-resolved serial crystallography studies of two heme containing proteins using a fixed target sample delivery system. Optimal parameters for successful photocage activation and nitric oxide release are explored.

Electron cryo-tomography of ATP synthase dimers in plant mitochondria indicates a wide dimer angle and a plant-specific subunit in the peripheral stalk.

A new satellite is discovered in the manganese Kβ spectrum using extended-range high-energy-resolution fluorescence detection. Advanced insights on its structure and evolution are extracted with principal component analysis.

Selective nuclear spin reversal by the method of adiabatic fast passage is a way to order a system of dynamically polarized nuclei. Using polarized neutron scattering, it increases the visibility of sources and sinks of proton polarization in radical proteins. Notably, Tyr369 has been confirmed as a potential radical site in bovine liver catalase.

This study identifies carbon crystal structures as 4-degree quotient graphs and proposes a novel approach for generating 3D 4-coordinate networks using 2D (2+1)-regular bipartite-like graphs. Through a random group and graph theory (RG2) method, we discover 509 new structures, including two low-energy phases (Pbam48 and Pbam40) that exhibit exceptional stability and potential applications as superhard carbon and quasi-direct band gap silicon materials in mechanical processing and solar photovoltaic technologies.

Quasicrystals are long-range-ordered materials with rotational symmetry incompatible with periodicity. Takakura et al. [(2025). IUCrJ 12, 435–443] present a study of a single grain of icosahedrite, the first natural icosahedral quasicrystal, which was found in a meteorite in 2009. Through detailed analysis of the diffraction peaks, they conclude that natural AlCuFe is an icosahedral quasicrystal superimposed by a phasonic modulation along the fivefold directions, which is similar to that observed in the synthetic quasicrystal. Based on knowledge of the synthesis and phase stability of icosahedral AlCuFe, they discuss the formation of icosahedrite in the meteorite.

This work demonstrates that high-quality ultra-fast total scattering data and pair distribution function data can be obtained from a single ∼30 fs pulse at the European XFEL, achieving a record Q range of up to 16.6 Å−1. These results establish XFELs as powerful tools for probing atomic scale structures on ultra-fast timescales, opening new opportunities for studying dynamic processes in disordered and complex materials.

Engineered in crystallo photosensitivity in a DNA-repair enzyme is carefully assessed for its suitability as a target for time-resolved crystallographic studies.

Crystallization is a fundamental non-equilibrium process in materials science, yet its early transient states remain difficult to probe experimentally. Möller et al. [(2025). IUCrJ 12, 462–471] use femtosecond X-ray scattering and X-ray cross-correlation analysis to reveal the structural evolution of defect-containing crystals forming in a supercooled noble-gas liquid.

Vitreous sectioning (CEMOVIS) is an alternative to FIB milling for generating thin samples suitable for cryo-EM imaging. We show that CEMOVIS samples preserve the high-resolution structural details of macromolecular complexes such as the 60S ribosome, despite the visible macroscopic damage visible in the samples.

A set of crystallographic structures has been obtained for the small antiviral protein LCB2 using molecular replacement models from six different structure-prediction programs. This set of structures can be interpreted as a multiconformer ensemble, improving quality metrics and offering an interesting insight into side-chain dynamics.

Single-crystal X-ray structures measured at around 20 K to high resolution were refined with structure-specific restraints from quantum chemical molecule-in-cluster and full-periodic computations, which permits benchmarking levels of theory of varying sophistication. Restraints can then `augment' low-quality crystal structures, with other possible applications.

This review commemorates the centenary of the Debye–Waller factor, highlighting its significance in quantifying the impact of thermal vibrations on scattering intensities as well as on crystal properties in small-molecule crystallography. It provides an introduction to thermal motion and displacement parameters, offering insights for chemists and crystallographers.

Combining improved diffraction methods, modeling approaches and advanced computations allows for a detailed understanding of atomic thermal motions in crystals. Thus, the Topical Review by Hoser & Madsen covers the Debye–Waller factor, the importance of anisotropic displacement parameters, and the interplay of experiment and theory to accurately capture collective atomic vibrations in molecular crystals.

We demonstrate an advanced scattering method for accessing the 3D reciprocal space of crystalline structures forming in a rapidly supercooled noble-gas liquid using a combination of femtosecond X-ray diffraction and X-ray cross-correlation analysis.

The refinement flexibility of the Hansen–Coppens multipole model is tested on DFT calculated structure factors for the tetra­kis­(μ-acetato)di­aquadicopper model system. The Cu scattering factor performs the best of all the options tried for most of the monitored parameters despite the Cu2+ nature of the complex studied. The Hansen–Coppens model performs similarly well when comparing deviations among computational chemistry methods.