Integral X-ray diffuse scattering for studying irradiation-induced dislocation loops in single crystals

A computational and experimental investigation of integral X-ray diffuse scattering near Bragg reflections with a wide-open detector is presented for the case of small circular irradiation-induced dislocation loops in metals. The large wavevector asymptotic power-law falloff for such loops is determined computationally and incorporated into numerical and analytical integral X-ray diffuse scattering cross-section calculations. These calculations are shown to enable the experimental determination of the size distribution and concentrations of irradiation-induced dislocation loops in single-crystalline tungsten.

An advanced approach combining solid-state NMR with powder diffraction applied to newly synthesized iso­thio­uronium salts

The synthesis of new tetra­fluoro­borate and bromide salts of iso­thio­uronium compounds is presented, followed by structural and spectroscopic studies, demonstrating that using solid-state NMR-derived intermolecular distances as a restriction can increase the likelihood of finding the crystal structure model when solving a crystal structure from powder diffraction data.

Rietveld refinement and NMR crystallographic investigations of multicomponent crystals containing alkali metal chlorides and urea

Three multicomponent crystals of the form MCl:urea·xH₂O (M = Li, Na, Cs) have been prepared with novel mechanochemical methods. Their crystal structures have been determined using an NMR-crystallography-guided Rietveld refinement that features the combined use of multinuclear solid-state NMR of quadrupolar nuclei, plane-wave density functional theory calculations and synchrotron powder X-ray diffraction data.

Crystallographic, electronic and vibrational properties of 2D silicate monolayers

The present work reports a density functional theory investigation of the structural, electronic, Raman and infrared properties of the (001) monolayer of phlogopite [K(Mg,Fe)₃Si₃AlO₁₀(OH)₂, with Mg/Fe ratio ≥ 2] and how they change with different Fe²⁺/Mg²⁺ substitutions in the octahedral sheet.

Electron-density analysis of halide⋯halide through-space magnetic exchange

We analyse both charge and spin degrees of freedom in the electron density of NiX₂(3,5-lutidine)₄ (X = Cl, Br and I) to understand the nature of magnetic exchange via through-space Ni²⁺–halide⋯halide–Ni²⁺ interactions. We propose that remarkably strong interactions can occur in coordination polymers when the exchange pathway is `switched-on' by just very weak covalency and enhanced by a charge density that is naturally localized on the ligand's atoms that bond to the magnetic metal ions.

The use of effective core potentials in Hirshfeld atom refinement: making quantum crystallography faster in NoSpherA2

A procedure is presented for the use of effective core potentials during wavefunction-based refinements. The refinement quality of the results is indistinguishable from that of all-electron calculations, with speedups of a factor of 2 for compounds containing heavy elements.

A generic cross-seeding approach to protein crystallization

A mixture integrating a wide variety of protein crystal fragments was used to obtain a new crystal structure of the human retinoblastoma binding protein 9.

A simple and robust high-pressure cell for transmission X-ray investigation

This work presents a simple and robust design for a high-pressure sample environment for in situ transmission X-ray diffraction, scattering and spectroscopy studies that facilitates combination with complementary techniques such as microscopy imaging and Raman spectroscopy. The cell is light; cheap; compatible with solids, gases and liquids; covers a temperature from 100 to 500 K; covers a pressure range from 0 to 350 bar; and exclusively has finger-tight connections.

A comparison of microcrystal electron diffraction and X-ray powder diffraction for the structural analysis of metal–organic frameworks

Microcrystal electron diffraction (microED) was used to determine the crystal structure of a recently synthesized metal–organic framework (MOF) from powder crystallites. The structural descriptions of two other MOFs by microED are compared with results previously published using X-ray powder diffraction supported by density functional theory calculations.

Fourier modal method for calculating neutron scattering from surface-relief and bulk diffraction gratings

A rigorous solution to the problem of neutron wave interaction with a periodic potential structure by the Fourier modal method is presented.

Epitaxial growth of bis­muth on CaF₂/Si(111): from planar films to self-organized arrays of nanostructures

The type, morphology, crystalline structure and character of faceting of Bi/CaF₂ planar films and self-organized arrays of nanostructures have been extensively studied for different growth temperature cases.

Chemical units of binary solid-solution alloys directly derived from short-range-order parameters

The present work provides a simple method to obtain the chemical unit of a solid-solution alloy directly using Cowley's short-range-order parameters α₁ and α₂.

Solid structure of Li₂BeF₄ (FLiBe) from room temperature to melting studied by neutron and X-ray diffraction

The volume expansion of Li₂BeF₄ upon melting is less than 5%. The equation describing the change in density of Li₂BeF₄ due to thermal expansion from room temperature to melting has been measured by neutron and X-ray diffraction, and the density is found to change depending on molecular weight and enrichment. Anisotropic volume expansion occurs in the crystal, and preferred orientation occurs in Li₂BeF₄ with the a unit-cell axes aligning with the direction of freezing front propagation.

A critical step toward far-field laboratory diffraction contrast tomography in Laue focusing geometry

A far-field laboratory diffraction contrast tomography (FF-LabDCT) technique is established and verified using conventional near-field LabDCT. Future directions to enhance FF-LabDCT as a versatile tool are outlined.

Computing virtual dark-field X-ray microscopy images of complex discrete dislocation structures from large-scale molecular dynamics simulations

A scalable forward model is developed to calculate virtual dark-field X-ray microscopy (DFXM) images of complex dislocation structures predicted by atomistic simulations, demonstrating the potential of DFXM to resolve features from dislocation multiplication and microstructural evolution.

Formalism to image the dynamics of coherent and incoherent phonons with dark-field X-ray microscopy using kinematic diffraction theory

A formalism to relate dark-field X-ray microscopy images to quantitative measurements of coherent and incoherent phonon populations in bulk single crystals is described.

Texture tomography with high angular resolution utilizing sparsity

This article reports non-destructive 3D texture mapping of a wide range of polycrystalline materials using synchrotron X-rays and utilizing the sparsity of the reconstructed texture.

Reliability of pair distribution function analysis in in situ experiments

The reproducibility of in situ pair distribution function studies of solvothermal reactions is investigated through detailed analysis of repeated measurements.

Deep-learning-powered desmearing for small-angle scattering

We present a novel deep-learning-based desmearing network (DSNet) that requires minimal simulation data for pre-training before fine-tuning. DSNet demonstrates excellent noise robustness and remarkable generalization performance, validated through both simulations and experiments.

Benchmarking deep learning for automated peak detection on GIWAXS data

Automated data processing is is needed to handle the vast amount of X-ray scattering data generated during grazing-incidence wide-angle X-ray scattering (GIWAXS) experiments. This publication provides a metric, dataset and baseline to assess the quality of a recent deep learning peak-detection method.

Insights into distorted lamellar phases with small-angle scattering and machine learning

This study employs Kolmogorov–Arnold networks to analyze neutron and X-ray scattering from distorted lamellar phases within a wave field representation, identifying topological defects and structural transitions. It offers insights into defect structures and their impact on material properties.

Probing the out-of-equilibrium dynamics of driven colloids by X-ray photon correlation spectroscopy

This article presents an application of X-ray photon correlation spectroscopy (XPCS) to probe the out-of-equilibrium dynamics in a driven colloidal system. XPCS enables the investigation of direction-dependent non-equilibrium dynamics and the gradual return of the suspension to equilibrium Brownian behaviour. The influence of such transient non-equilibrium dynamics needs to be taken into consideration when dynamic scattering methods are used for micrometre-range particle measurement.

Form factor of prismatic particles for small-angle scattering analysis

A new tool for form factor analysis of any n-sided nanoprism is presented. Shape analysis of various gold and/or silver nanoprisms (n = 3, 4, 5) is conducted using small-angle X-ray scattering experimental data. Our method compares well with transmission electron microscopy image analysis, providing additional details about the nanoprisms, and significantly reduces computation time compared with all-atom simulations.

Optimal st-PMMA/C₆₀ helical inclusion complexes via tunable energy landscapes for the application of an Ag SERS-active substrate

This study tunes the energy landscape of the syndiotactic poly(methyl methacrylate) (st-PMMA)/C₆₀/toluene complex system and finds the efficient pathway to form the thermodynamically favored st-PMMA/C₆₀ complex by temperature modulation. This st-PMMA/C₆₀ complex architecture further acts as a photoreduction site for yielding the Ag surface-enhanced Raman scattering (SERS)-active substrate for advanced chemical sensing applications.

Solvent-annealing-induced microphase separation in polyether polyurethane: a small-angle X-ray scattering study

Small-angle X-ray scattering was applied to polyether polyurethane to investigate the effects of solvent vapor annealing on the microphase separation. Among the solvents studied, methyl ethyl ketone induced the greatest degree of phase separation in polyurethane compared with the thermally annealed state.

In situ small-angle X-ray scattering measurement at the Very Small Angle Neutron Scattering Instrument at the China Spallation Neutron Source

A pioneering vertical-geometry small-angle X-ray scattering setup is available at beamline 14, Very Small Angle Neutron Scattering Instrument, at the China Spallation Neutron Source. Small-angle X-ray and neutron scattering can thus be performed at the same time.

Upgrade of the KWS-2 high-intensity/extended-Q-range SANS diffractometer of JCNS for soft matter and biophysics: in situ SEC, controlled in situ RH/T variation and WANS detection

Upgrades at the KWS-2 small-angle neutron scattering (SANS) diffractometer at Jülich Centre for Neutron Science (JCNS) for an optimal sample quality for biological systems [in-beam size-exclusion chromatography (SEC) complementarity], controlled humidity and temperature (RH/T) on ionic conductive samples and biological membranes, and diffraction capability (wide-angle neutron scattering, WANS) are reported.

Size-exclusion chromatography–small-angle neutron scattering system optimized for an instrument with medium neutron flux

Incorporating a size-exclusion chromatography–small-angle neutron scattering (SANS) system for a SANS instrument with medium neutron flux has resulted in the successful observation of the scattering profiles of target components in complexes.

SAStutorials.org – online tutorials on small-angle scattering data analysis

We present SAStutorials.org, a website that hosts online tutorials for small-angle scattering data analysis through active learning.

XRDplayground: a Python-based educational tool for interactive learning of powder X-ray diffraction crystallography

To enhance learning through visualization, we present XRDplayground, an open-source software developed in Python that simultaneously simulates the unit cell and its powder X-ray diffraction pattern.

If you cannot see it, is it still there?

Flexible segments of protein molecules, while known to be present in a structure, are often not visible in the electron density and are thus omitted in models. Ensemble refinement of completed models allows for visualization and exploration of the available conformation space of such `invisible' regions. Combined with the analysis of different crystal forms, this enables insights into functional aspects of molecular plasticity to be inferred.

Complete online database of maximal subgroups of subperiodic groups at the Bilbao Crystallographic Server

The complete maximal subgroups of subperiodic groups database of the Bilbao Crystallographic Server is presented. The program MAXSUB gives online access to all maximal non-isotypic as well as all maximal isotypic subgroups of indices up to 9, and to the series of maximal isotypic subgroups of subperiodic groups.

RamPlot: a webserver to draw 2D, 3D and assorted Ramachandran (φ, ψ) maps

A web server has been developed to draw and analyse 2D and 3D Ramachandran maps, enabling users to easily visualize and assess torsion angles, including those from non-standard residues, across multiple protein structures. RamPlot also facilitates the visualization of torsion angles across three rotatable bonds and monitors conformational transitions during molecular dynamics simulations.