Crystal structure and elastic and phonon properties of realgar versus pressure

The present work reports on a density functional theory characterization of realgar, α-As₄S₄, a mineral made of cluster-like As₄S₄ molecules held together by weak van der Waals interactions that has recently drawn attention for possible optoelectronic applications. A challenge in dealing with theoretical methods with this kind of crystalline system is the inclusion of dispersive forces in the physical treatment and the correction of basis set superposition error in molecule–molecule interactions, which are both accounted for here using the PBEh-3c approach.

De­hydroxy­lation and structural transition in α-GaOOH investigated by in situ X-ray diffraction

The hydroxyl group in α-GaOOH supports the [GaO₆] octahedron tunnel while squeezing Ga³⁺ away from the center of the [GaO₆] octahedron to form a distorted octahedron. De­hydroxy­lation stimulates the Ga—O bond inside the double chains to break preferentially, generating square-wave-like octahedron chains that reconstruct into the α-Ga₂O₃ structure.

Visualizing the fibre texture of satin spar using laboratory 2D X-ray diffraction

A simple symmetric 2D scan using a point focus beam was used to determine the fibre axis of fibre-textured satin spar samples. A geometric explanation of the `wing' feature formed by the diffraction spots in 2D scans helps to visualize the nature of the reciprocal layers of the fibre-textured samples through wide-range reciprocal space mapping.

Revisiting the hydrogenation behavior of NdGa and its hydride phases

Detailed investigation of the NdGa–H(D)₂ systems led to the unambiguous identification of two distinct phases. It was found that NdGaH(D)_y (1.1 ≥ y ≥ 0.9) has a onefold structure while NdGaH(D)_x (1.6 ≥ x ≥ 1.2) adopts a threefold superstructure.

Tripling of the scattering vector range of X-ray reflectivity on liquid surfaces using a double-crystal deflector

A straightforward method is presented for aligning a double-crystal deflector for X-ray diffraction measurements on liquid surfaces. This method allows the measurement of liquid surfaces and interfaces in a high q_z range not achievable up to now.

Convolutional neural network approach for the automated identification of in cellulo crystals

Open-source deep-learning algorithms (Mask R-CNN) are used to automatically identify intracellular crystals in living insect cell cultures.

X-ray diffraction from dislocation half-loops in epitaxial films

X-ray diffraction from dislocation half-loops consisting of a misfit segment with two threading arms extending from it to the surface is calculated by the Monte Carlo method.

Refinement of the uranium dispersion corrections from anomalous diffraction

Two new routines for the refinement of uranium dispersion corrections from anomalous powder diffraction data, using either the intensity of some reflections or full-pattern Rietveld refinement, are reported. These methods advance the application of diffraction anomalous fine structure on uranium compounds, and open up new possibilities for the assessment of complex materials such as mixed-valence compounds.

Dynamical and kinematical X-ray diffraction in a bent crystal

On the basis of dynamical and kinematical theories, X-ray diffraction in strongly and weakly bent crystals is simulated. The distribution of diffraction intensity inside a bent crystal is shown for the first time as a function of the bending radius.

A high-temperature high-pressure small-angle neutron scattering cell for studying hydro­thermal reactions in supercritical water

A robust high-temperature high-pressure cell with a metal window for small-angle neutron scattering (SANS) experiments has been developed. This cell enables in situ SANS experiments on materials within sub- and supercritical water environments.

Millisecond X-ray reflectometry and neural network analysis: unveiling fast processes in spin coating

This work demonstrates high-resolution X-ray reflectometry measurements with millisecond time resolution as a quantitative method for fast in situ measurements.

A workflow for single-particle structure determination via iterative phasing of rotational invariants in fluctuation X-ray scattering

A single-particle structure determination pipeline is implemented in the open-source software xFrame, which includes methods for determining rotational invariants from X-ray scattering patterns and performing structure reconstructions by iterative phasing of rotational invariants.

Polarized X-ray diffraction anomalous near-edge structure study on the orbital physics of thin WSe₂ layers

This work demonstrates the capability of polarization-dependent diffraction anomalous near-edge structure to differentiate and analyse the valence orbital structure of few-layer WSe₂ around the band edge.

Observations of specimen morphology effects on near-zone-axis convergent-beam electron diffraction patterns

Symmetries in the intensity distributions of convergent-beam electron diffraction (CBED) patterns are governed not only by the atomic structure of the unit cell but by the morphology of the diffracting specimen as a whole. A simple interpretation based on structural tilt projections and the multislice scattering theory may prove useful in extracting morphological information embedded in the presence or absence of CBED pattern symmetries for a wide range of applications, from 4D scanning transmission electron microscopy to bonding electron density studies in nano-structured materials.

Simulations of dislocation contrast in dark-field X-ray microscopy

Forward projections of detector images are generated using two complementary simulation tools based on geometrical optics and wavefront propagation, respectively. The feasibility of observing dislocations in a domain wall is elucidated as a function of different instrumental settings, scan modes, dislocation densities in the wall and spatial resolution.

Wetting of alginate aerogels, from mesoporous solids to hydrogels: a small-angle scattering analysis

A mathematical model is proposed to analyse the small-angle neutron scattering of increasingly wet alginate aerogels as they progressively transform from a mesoporous solid into an aqueous gel.

The multi-slit very small angle neutron scattering instrument at the China Spallation Neutron Source

The first spallation neutron source based very small angle neutron scattering instrument has been constructed and accepted at the China Spallation Neutron Source. The instrument finds applications in multidisciplinary fields of soft matter, condensed matter physics, materials science and others.

DLSIA: Deep Learning for Scientific Image Analysis

This article introduces DLSIA (Deep Learning for Scientific Image Analysis), a user-friendly Python library that provides scientists and researchers with a number of convolutional neural networks with customizable architectures for a variety of image analysis tasks, enabling accelerated discoveries and enhancing interdisciplinary collaboration in the face of growing experimental data complexity.

Simulation of neutron dark-field data for grating-based interferometers

The Python-based library correlogram-tools makes use of existing small-angle scattering models and a numerical implementation of the Hankel transform to simulate dark-field interferometry data. This software can be used to inform researchers of viable sample sets for interferometry experiments, analyze interferometry data, and simulate raw and reconstructed interferometry images for the training of more advanced segmentation models and analysis protocols.

Robust image descriptor for machine learning based data reduction in serial crystallography

This paper proposes a pipeline to categorize serial crystallography data, consisting of a real-time feature extraction algorithm, an image descriptor and a machine learning classifier. This approach demonstrates superior performance compared with other feature extractors and classifiers.

Study of the epitaxy between ɛ-Fe₂O₃, hematite and spinel in brown-glazed Chinese ceramics using electron diffraction mapping techniques

The possibilities of using transmission Kikuchi diffraction (TKD) to investigate historical materials are demonstrated through a study of ancient and recreated Chinese brown-glazed ceramics. This work emphasizes the importance of understanding the complex crystalline structures found in glazes to document the growth mechanisms and tackles the specificities of studying such samples with TKD and automated crystal orientation mapping–precession electron diffraction.

A correction procedure for secondary scattering contributions from windows in small-angle X-ray scattering and ultra-small-angle X-ray scattering

The high scattering power of a sample at low angles may lead to significant secondary scattering contributions in the measured small- and ultra-small-angle X-ray scattering patterns. A correction procedure is presented for the removal of the excess intensity and to improve the dynamic range of the measurement.

A new experimental station for microbeam X-ray scattering at the SSRF BL10U1 beamline

This work describes the newly constructed time-resolved microbeam small-angle X-ray scattering experimental station at the BL10U1 beamline at the Shanghai Synchrotron Radiation Facility.

Neural network analysis of neutron and X-ray reflectivity data incorporating prior knowledge

This study addresses the ambiguity related to the phase problem as a primary obstacle in machine-learning-based approaches for extracting information from X-ray reflectivity and neutron reflectivity data. The proposed solution is a procedure that enables training of a neural network on a continuous range of smaller subspaces of a large parameter space.

Laue microdiffraction on polycrystalline samples above 1500 K achieved with the QMAX-µLaue furnace

A unique X-ray Laue microdiffraction setup and alignment procedure allowing measurements of the microstructure and strain field in polycrystalline specimens at temperatures as high as 1500 K has been developed at beamline BM32, ESRF, making use of a new version of the QMAX furnace.

X-ray standing wave characterization of the strong metal–support interaction in Co/TiO_x model catalysts

X-ray standing waves on a thermally stable periodic multilayer have been used to evidence the partial coverage of Co nanoparticles by a titanium oxide support in a model catalyst, following high-temperature reduction. The developed approach has potential for fundamental studies in thermally activated surface processes in catalysis, membranes and metallurgy.

A note on the Hendrickson–Lattman phase probability distribution and its equivalence to the generalized von Mises distribution

The equivalence between the Hendrickson–Lattman phase probability distribution and the generalized von Mises distribution of order two is documented using both formulae and figures.

Measurements of the geometrical characteristics and refractive index of specimens made with X-ray interferometers

Using an X-ray triple Laue interferometer, the radius and the refractive index of specimens having plano-concave form are determined.

Unlocking the surface chemistry of ionic minerals: a high-throughput pipeline for modeling realistic interfaces

PolyCleaver is an automated Python-based pipeline for modeling ionic mineral interfaces with polyatomic anions, providing new insights into potential catalytic properties and broadening the exploration of synthetic pathways in complex mineral systems.

INSIGHT: in situ heuristic tool for the efficient reduction of grazing-incidence X-ray scattering data

INSIGHT is a Python-based software tool for reducing and batch processing large grazing-incidence wide- and small-angle X-ray scattering data sets and extracting structural, orientational and morphological information on thin films.

The Pixel Anomaly Detection Tool: a user-friendly GUI for classifying detector frames using machine-learning approaches

A novel user-friendly highly modular graphical user interface based tool is reported for sorting X-ray diffraction patterns by implementing machine learning. In a supervised learning approach, the tool can easily be used to identify and sort data containing specific experimental artefacts, or trained to perform routine data-analysis tasks such as hit finding.

PYXIS: an integrated software package for synchrotron micro/nanodiffraction data analysis

A custom-developed software package, PYXIS, is introduced for the in-depth analysis of synchrotron X-ray micro/nanodiffraction data. Novel algorithms employed by this software package include zone-axis assisted indexing, a strategy for serial peak position comparison and automated dislocation characterization based on the Wilkens model.

FlɛX: a computer vision program to evaluate strain in flexible crystals

A program has been developed to assist researchers interested in bending crystals to evaluate crystal deformation from a single optical image.

X-Ray Calc 3: improved software for simulation and inverse problem solving for X-ray reflectivity

This work introduces X-Ray Calc 3, an open-source software package for simulating X-ray reflectivity (XRR) and reconstructing film structures on the basis of measured XRR curves, featuring a user-friendly interface and improved fitting capabilities.

iRing: a program for two-dimensional powder diffraction image integration with automatic calibration

iRing is a processing program that utilizes the Hough transform to automate peak finding and calibration, greatly improving the speed and ease of calibrating two-dimensional diffraction images collected by image detectors.

iQual: a new computer program for qualitative phase analysis with efficient search–match capability

iQual is a computer program that utilizes the optimized Crystal_db database, derived from the Crystallography Open Database, for efficient searching and matching of experimental X-ray diffraction patterns for qualitative phase analysis, employing a two-step approach and matrix operations for enhanced efficiency.

FLEXR GUI: a graphical user interface for multi-conformer modeling of proteins

This article describes a graphical user interface (GUI) for the multi-conformer modeling program FLEXR, designed as a plugin within Coot 1. At the click of a button, the GUI allows seamless integration of FLEXR into the crystallographic modeling and validation pipeline within Coot.

SEB: a computational tool for symbolic derivation of the small-angle scattering from complex composite structures

Scattering Equation Builder (SEB) is a C++ library for symbolically deriving form factors for composite structures built by linking sub-units to each other.

From solution to structure: empowering inclusive cryo-EM with a pre-characterization pipeline for biological samples

The European Synchrotron's Solution-to-Structure (SOS) pipeline streamlines cryo-EM studies, providing an inclusive process from grid preparation to high-resolution data collection for single-particle analysis and cryo-electron tomography. This service is especially tailored for users with restricted or no access to cryo-EM infrastructure, enabling them to conduct screening experiments and acquire samples suitable for high-resolution data collection.