New Fourier-Based Framework for Analyzing Crystal Shape and Lattice Deformation in Powder Diffraction
Researchers have introduced a generalized Fourier-based mathematical framework that allows crystal-domain shape, lattice deformation, and their relative orientation to be modelled simultaneously in powder diffraction analysis. Current methods are limited to a small set of ideal geometric shapes, leaving complex or deformed nanocrystalline particles poorly characterized. The advance could improve the accuracy of microstructural information extracted from nanomaterials, with potential implications for materials science and related fields.
A preprint submitted to the Journal of Applied Crystallography presents a unified Fourier-based formalism for powder diffraction that treats crystal-domain shape deformation, lattice deformation, and relative shape-lattice misorientation as independently refinable tensor operations. Existing approaches rely on so-called common-volume functions, for which analytical solutions exist only for a limited number of idealized geometries, restricting their applicability to real-world nanocrystalline materials. The new framework enables continuous affine transformations of both crystal shape and lattice simultaneously, while still allowing analytical evaluation of directional Fourier coefficients. This means complex particle shapes, anisotropic deformations, and arbitrary orientational relationships between shape and lattice can all be captured within a single reciprocal- and real-space model. The method is applicable to individual diffraction peaks, full powder patterns, and total-scattering shape corrections. Validation using virtual scattering experiment data showed that crystal size, shape, lattice deformation, and shape-lattice orientation could be recovered simultaneously with high accuracy. The work was submitted in June 2026 and has not yet undergone peer review.
What's missing
The authors do not appear to report tests on experimental (as opposed to simulated/virtual) diffraction data, leaving open questions about performance under real measurement noise, instrumental artifacts, and sample polydispersity. Computational cost and scalability to large datasets are not discussed.
What different sources said
- arXiv physicsCenter
Crystal Shape and Lattice Deformation in Powder Diffraction
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.