Rapid screening of in cellulo grown protein crystals via a small-angle X-ray scattering/X-ray powder diffraction synergistic approach

A rapid and sensitive detection approach utilizing high-brilliance and low-background small-angle X-ray scattering and X-ray powder diffraction to detect protein microcrystals grown within living insect cells is described.

Neutron diffraction measurements of weld residual stresses in three-pass slot weld (Alloy 600/82) and assessment of the measurement uncertainty

Residual strain measurements were conducted on an Alloy 600/82 weld on five diffractometers, and two different approaches were used to analyse the data and estimate the stresses. The large body of data enabled estimation of the Bayesian mean of the residual stress distribution and a statistically robust estimation of the residual stress uncertainty associated with the method.

X-ray phase-contrast topography to measure the surface stress and bulk strain in a silicon crystal

It is shown that the surface finishing has measurable effects on the bulk strain field of a 0.8 mm-thick Si crystal, at the level of a few parts in 10⁹. In particular, it is shown that the strain due to a Cu film a few nanometres thick is well modelled by a surface stress (equiaxial and uniform) equal to 0.29 (2) GPa × t, where t is the film thickness. This result is consistent with the stress thickness values given in the literature for similar interfaces.

Simulation of X-ray diffraction in a cylindrical crystal

The dynamical and kinematical X-ray diffraction in a cylindrical crystal has been simulated. The calculated distributions of reflection and transmission X-ray intensity inside the cylindrical crystal are obtained, as well as reciprocal space maps.

Grazing-incidence X-ray diffraction investigation of the coincidence site lattice of the Ge/Si(001) system

Grazing-incidence X-ray diffraction analysis of the coincidence site lattice formed by interfacial misfit dislocations in Ge/Si(001) heteroepitaxy is reported for a wide variety of Ge layer thicknesses ranging from 10 to 580 nm.

InsteaDMatic: towards cross-platform automated continuous rotation electron diffraction

A DigitalMicrograph script named InsteaDMatic has been developed for automated continuous rotation electron diffraction (cRED) data acquisition. InsteaDMatic coordinates functions of the transmission electron microscope goniometer and camera in order to tune up diffraction-frame recording simultaneously with crystal rotation. Exploiting fast and automated data collection, the influence of the electron dose rate on the quality of cRED data was studied, and structural models obtained for two different parallel-beam illumination modes (aperture selection and nanoprobe) were compared.

Accurate and time-saving qu­antification of a component present in a very small amount in a mixture by the direct derivation method

A procedure for accurate and time-saving quantification of a component that is present in a very small amount in a mixture using the direct derivation method is proposed. Test results demonstrate that crystalline phases of 0.02–0.4 wt% in binary mixtures could be quantified with errors of 0.01–0.03 wt%. Quantification of a small amount of an amorphous component is also discussed.

X-ray scattering from a plane parallel slab using radiation transfer considerations

The X-ray scattering power of a plane parallel homogeneous slab of material is interpreted using radiation intensity transfer considerations.

Localization and steric effect of the lone electron pair of the tellurium Te⁴⁺ cation and other cations of the p-block elements. A systematic study

This article presents a geometrical method to localize and model the steric effect of lone pairs (LPs) of cations of the p-block elements as well as the trends of the LP size and displacement from the cation core in the periodic table.

Net atomic charges, electric moments, and sign and magnitude of optical rotatory power in α-TeO₂ at 296 K

Optical activity is determined from a point charge model in α-TeO₂ (paratellurite). Atomic charges of Te and O are iterated, electric moments, axial vectors and gyration tensor components are defined, and the optical rotatory power and its sense are determined.

Polarimetric studies of L-arginine-doped potassium di­hydrogen phosphate single crystals

A comprehensive investigation of optical anisotropy parameters based on the different methods of high-accuracy polarimetry has been applied to characterize potassium dihydrogen phosphate crystals doped in the range of 0.7–3.8 wt% with L-arginine amino acid.

Controllable formation of unusual homocrystals in poly(L-lactic acid)/poly(D-lactic acid) asymmetric blends induced by the constraining effects of pre-existing stereocomplexes

Synchrotron radiation wide-angle X-ray diffraction and small-angle X-ray scattering techniques have been used to investigate and elucidate the formation conditions, mechanism and phase transition of an unusual homocrystalline polymorph in stereocomplexable polymers.

Ptychography at the Linac Coherent Light Source in a parasitic geometry

X-ray ptychography is used to illustrate the high quality and high coherence of a `parasitic' beam in an X-ray free-electron laser. Use of such geometries would greatly increase the availability of beamtime at these large-scale high-demand facilities.

Analyzer-free linear dichroic ptychography

To characterize the transmission matrix and determine the crystal or orbital orientation in a material with high-resolution mapping of transmission properties, the linear-dichroism scattering model in ptychographic imaging is introduced. Via the proposed efficient two-stage reconstruction algorithm, the dichroic transmission matrix can be recovered without an analyzer by using ptychography measurements with as few as three different polarization angles.

Density-based clustering of crystal (mis)orientations and the orix Python library

Data clustering incorporating symmetry is applied to crystal orientations and misorientations and the orix Python library for crystal orientation analysis is introduced.

Discrete spherical harmonic functions for texture representation and analysis

This paper describes the discrete harmonics basis set on S² and S³ spheres using the finite element method for texture representation.

X-ray diffraction reveals the amount of strain and homogeneity of extremely bent single nanowires

The bending radii and strain of individual nanowires are determined using X-ray diffraction with a nano-focused beam and a dedicated diffraction theory for strongly bent crystals. Electron microscopy investigations corroborate the results.

On the Hirshfeld surface for copper(II) atoms in different coordination environments

The properties of Hirshfeld surfaces around Cu(II) atoms in coordination complexes are sensitive to coordination geometry and weak interactions.

Misorientation relationships in goethite, hematite and magnetite: a case study of iron-formation rocks from the Iron Quadrangle, Brazil

According to this study, it is possible to observe that the transformation between magnetite, hematite and goethite occurs in the solid state, with the newly transformed goethite inheriting the crystallographic orientations of the former crystals, and that this phenomenon is better recognized by combining observations of misorientation relationships.

Temperature evolution of Fe–27Ga structure: comparison of in situ X-ray and neutron diffraction studies

The temperature-induced phase transformations in Fe–27Ga alloy have been studied by comparison of in situ X-ray and neutron diffraction. It is determined that the phase transitions on the surface and in the volume of the bulk Fe–27Ga sample occur in different manners.

Bragg coherent imaging of nanoprecipitates: role of superstructure reflections

Detailed numerical simulations are presented, aimed at demonstrating the relevance of Bragg coherent diffraction imaging for elucidating coherent nanoprecipitates and more generally chemically ordered phases

Instrument-model refinement in normalized reciprocal-vector space for X-ray Laue diffraction

An instrument-model refinement method for X-ray Laue data is presented and tested. It is shown that the approach works well even when the initial geometrical parameters deviate significantly from the target values.

Small-angle X-ray scattering as a multifaceted tool for structural characterization of covalent organic frameworks

Small-angle X-ray scattering models are applied to covalent organic frameworks in order to analyse fractal parameters and structure–scattering relationships.

Generalizing small-angle scattering form factors with linear transformations

An approach utilizing transforms of nanoparticles is introduced, which allows exact solutions for any nanoparticle that can be approximated through any combination of scaling, shear, rotational and inversion transformations of a known structure.

XtalCAMP: a comprehensive program for the analysis and visualization of scanning Laue X-ray micro-/nanodiffraction data

XtalCAMP is a MATLAB-based software package suitable for the analysis and visualization of scanning Laue X-ray micro-/nanodiffraction data. The graphical user interfaces allow the easy analysis of characteristic microstructure features, including real-time intensity mapping for a quick examination of phase, grain and defect distribution, 2D color-coded mapping of crystal orientation, principal strain/stress analysis, and strain ellipsoid representation, as well as a series of additional toolkits.

PyNX: high-performance computing toolkit for coherent X-ray imaging based on operators

PyNX is a toolkit with assorted Python modules and command-line scripts which can be used for the analysis and simulation of coherent X-ray imaging, including techniques such as coherent diffraction imaging, ptychography and wavefront propagation, in the near- or far-field regime. All calculations can be executed solely on graphical processing units (GPUs) for accelerated computing. Elementary algorithms can be easily tailored, built upon and combined using an operator-based approach, allowing full flexibility with high-performance computing. Calculations can be distributed on multiple GPUs using MPI, e.g. for large ptychography data sets.