The structure of gold nanoparticles: molecular dynamics modeling and its verification by X-ray diffraction

This paper presents results of molecular dynamics simulations of gold nanoparticles and their experimental verification by means of X-ray diffraction. The conducted studies reveal that structural disorder in gold nanoclusters is related to surface effects and vacancies.

Combined X-ray and neutron single-crystal diffraction in diamond anvil cells

It is shown that it is possible to perform combined X-ray and neutron single-crystal studies in the same diamond anvil cell. The data processing procedures and a joint structural refinement of the high-pressure synchrotron and neutron single-crystal data are presented and discussed for the first time.

Accurate background correction in neutron reflectometry studies of soft condensed matter films in contact with fluid reservoirs

The background field arising from neutron-beam scattering from reflectometry liquid cells is calculated and compared with experimental measurements. Use of the entire background field for background subtraction in neutron reflectometry measurements represents a significant improvement in accuracy and reduction of measurement uncertainty.

Hierarchical structure of the triclinic α-phase crystal in nylon 6,12 mediated by two-dimensional confinement

With cross-analysis of electron and X-ray diffraction results, a cylindrically confined hierarchical assembly of molecular chains, unit cells, hydrogen-bonded sheets and lamellae is demonstrated in the triclinic α-phase crystals of nylon 6,12.

High-precision face-centered cubic–hexagonal close-packed volume-change determination in high-Mn steels by X-ray diffraction data refinements

A simple full-pattern refinement model has been developed to study Fe–Mn-based alloys. The model can be used to extract accurate lattice parameters from a single X-ray diffraction measurement of a textured multiphase sample.

Stable sample delivery in viscous media via a capillary for serial crystallography

A sample-delivery method for serial crystallography is introduced, which uses a capillary and a viscous medium.

Tuning the optical isotropic point of mixed crystals of ethylenedi­ammonium sulfate/selenate

The isotropic point of a uniaxial bianisotropic mixed crystal is shifted by controlling the concentration of an anion impurity in a solid-solution series. A tunable set of iso-index bandpass filters is proposed.

Real- and Q-space travelling: multi-dimensional distribution maps of crystal-lattice strain (∊₀₄₄) and tilt of suspended monolithic silicon nanowire structures

A multiscale analytical approach is presented for understanding the structure of micro- and nano-fabricated nanowire-based sensors. Using scanning X-ray diffraction microscopy, crystal deformation is evaluated with respect to lattice strain and tilt caused by the manufacturing process of a silicon monolith.

The nondestructive measurement of strain distributions in air plasma sprayed thermal barrier coatings as a function of depth from entire Debye–Scherrer rings

A 2D method employing whole (or part) Debye–Scherrer rings has been used to obtain a more accurate and reliable strain-mapping result for high-density thermal barrier coatings. The method has other applications, but the use of very high energy synchrotron light makes the study of a highly anisotropic microstructure more tractable.

A routine for the determination of the microstructure of stacking-faulted nickel cobalt aluminium hydroxide precursors for lithium nickel cobalt aluminium oxide battery materials

Stacking faults and interstratification faults in a cobalt- and aluminium-bearing nickel layered double hydroxide used as a precursor for Li(Ni_1−x−yCo_xAl_y)O₂ battery materials were quantified by a combination of a grid-search approach and a recursive routine for generating and averaging supercells of stacking-faulted layered substances implemented in the TOPAS software.

Neutron Larmor diffraction on powder samples

A method to analyse neutron Larmor diffraction data from polycrystalline samples is presented.

Determination of the full deformation tensor by multi-Bragg fast scanning nano X-ray diffraction

A method for determining the full deformation tensor from a scanning nano X-ray diffraction experiment mapping two Bragg peaks is described.

Accuracy and precision of near-field high-energy diffraction microscopy forward-model-based microstructure reconstructions

A direct comparison is made between electron backscatter diffraction and near-field high-energy diffraction microscopy measurements. A small gold oligocrystal is characterized, and reconstructed orientations and grain-boundary positions are evaluated.

Density-functional-theory-predicted symmetry lowering from cubic to tetragonal in nickel hexa­cyano­ferrate

Van der Waals corrected density-functional-theory computations predict a new tetragonal (P4m2) equilibrium crystal structure for nickel hexa­cyano­ferrate, an F43m-structured Prussian blue analogue.

Chord-length distributions cannot generally be obtained from small-angle scattering

The methods used to estimate chord-length distributions from small-angle scattering data assume a structure made up of spatially uncorrelated and convex regions. Significant errors follow from applying these methods outside of their range of validity.

Best practices for operando depth-resolving battery experiments

Experimental considerations for quantitative depth-resolving operando X-ray scattering measurements in a radial transmission geometry are identified.

Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization

Grazing-incidence small-angle X-ray scattering coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. In this study, to optimize the CT image quality, total variation regularization is introduced to minimize sinogram image noise and artifacts.

Structure analysis of supported disordered molybdenum oxides using pair distribution function analysis and automated cluster modelling

Using pair distribution function analysis, the structure of amorphous supported molybdenum oxides is characterized using a new automated data modelling approach.

K-space algorithmic reconstruction (KAREN): a robust statistical methodology to separate Bragg and diffuse scattering

A robust statistical methodology is described whereby Bragg diffraction is separated from the total scattering without altering the underlying diffuse scattering. Subsequent evaluation of the diffuse scattering by pair distribution function methods reveals unprecedented detail on the system's real structure.

Multi-wavelength Bragg coherent X-ray diffraction imaging of Au particles

Multi-wavelength Bragg coherent X-ray diffraction imaging is demonstrated on a single Au particle. The reconstructed Bragg electron density and phase field are in excellent agreement with the results obtained from conventional rocking scans of the same particle.

Optimized reconstruction of the crystallographic orientation density function based on a reduced set of orientations

In this work, a new method is developed to reconstruct the orientation distribution function from experimental data with a set of equally weighted orientations. It is based on the deterministic integer approximation method, but it minimizes the shortcomings of this method by optimizing the orientation grid and kernel function.

Bragg-edge attenuation spectra at voxel level from 4D wavelength-resolved neutron tomography

A wavelength-resolved neutron tomography study is performed on a reference sample made of several polycrystalline materials, namely nickel, iron, titanium, lead, copper and aluminium. Wavelength-resolved total cross sections for each material and for each voxel in the reconstructed volume of the sample were retrieved.

Qu­antifying nanoparticles in clays and soils with a small-angle X-ray scattering method

This paper describes a method to quantify nanoparticles in clays and soils with small-angle X-ray scattering.

Li-ion half-cells studied operando during cycling by small-angle neutron scattering

Lithium-ion half-cells are studied in situ and operando by small-angle neutron scattering. The variation in the signal can be explained by the lithiation of graphite in the sample.

Stress-induced C14→C15 phase transformation in a Zr(Fe,Cr)₂ Laves structured nanophase

The stress-induced C14→C15 phase transformation in an individual nanophase was explored by means of the transmission electron microscopy technique.

Mercury 4.0: from visualization to analysis, design and prediction

An overview of Mercury 4.0, an analysis, design and prediction platform that acts as a hub for the entire Cambridge Structural Database software suite, is presented.

BILMIX: a new approach to restore the size polydispersity and electron density profiles of lipid bilayers from liposomes using small-angle X-ray scattering data

The use of the BILMIX program to model small-angle X-ray scattering data of model membranes and deliver a description of the lipid bilayer electron density and vesicle size distribution is presented.

Multifitting: software for the reflectometric reconstruction of multilayer nanofilms

Multifitting, a computer program designed specifically for modeling the optical properties of multilayer films over a wide range of wavelengths, is described. The key features of Multifitting are the ability to work simultaneously with an arbitrary number of experimental curves and an ergonomic graphical user interface that is designed for intensive daily use in the diagnosis of thin films.

IPCAS: a direct-method-based pipeline from phasing to model building and refinement for macromolecular structure determination

The pipeline IPCAS (Iterative Protein Crystal structure Automatic Solution) integrates the direct-method program OASIS and other protein crystallography programs for experimental phasing and model building, with emphasis on direct-method single-wavelength anomalous diffraction/single isomorphous replacement phasing and direct-method-aided partial-structure extension.

BornAgain: software for simulating and fitting grazing-incidence small-angle scattering

BornAgain is a free and open-source multi-platform software framework for simulating and fitting X-ray and neutron reflectometry, off-specular scattering, and grazing-incidence small-angle scattering (GISAS). This paper concentrates on GISAS.

PyMDA: microcrystal data assembly using Python

A Python program to assemble radiation-damaged and partial diffraction data sets from microcrystals is described.

crystalAligner: a computer program to align crystal directions in a scanning electron microscope by global optimization

A computer program has been developed for aligning one or two crystal directions in crystals of arbitrary orientation and structure with the coordinate system of a scanning electron microscope. The crystal alignment is globally optimized even for highly constrained cases and may support the microscopy analysis of anisotropic properties, establishment of specific diffraction conditions and preparation of pre-aligned electron-transparent lamellae.

A simple sample-changing robot for grazing-incidence X-ray scattering

A simple sample-changing robot has been designed and built for combinatorial studies using grazing-incidence scattering.

A fast-cooling sample-positioning probe for low-temperature neutron scattering experiments

The design of sample-positioning probes used in top-loading cryostats is investigated in order to optimize sample cool-down time.

Detailed surface analysis of V-defects in GaN films on patterned silicon(111) substrates by metal–organic chemical vapour deposition. Corrigendum

An error in the article by Gao, Zhang, Zhu, Wu, Mo, Pan, Liu & Jiang [J. Appl. Cryst. (2019), 52, 637–642] is corrected.

Cyrus Cho­thia (1942–2019)

Catalina Ruiz-Pérez (1957–2019)

On the 80th birthday of Professor (retired) Dr Dr h.c. Peter Paufler

NMR Multiplet Interpretation: an Infographic Walk-through

Molecular Symmetry and Group Theory. Approaches in Spectroscopy and Chemical Reactions