Journal of Applied Crystallography最新文献

{"title":"Tetragonal distortion of the multiferroic compound α-LiFe₅O₈ from first-principles calculations.","authors":"Yaoshi Cheng, So-Hyun Park","doi":"10.1107/S1600576726006709","DOIUrl":"10.1107/S1600576726006709","url":null,"abstract":"<p><p>The cubic space group <i>P</i>4₃32 has been previously reported for the multiferroic lithium ferrite (α-LiFe₅O₈, denoted LFO). Instead, results from the present study using PBEsol+<i>U</i> calculations with SSSP pseudopotentials suggest that the tetragonal space group <i>P</i>4₃2₁2 is true for the ground state of LFO. Spin-resolved projected density of states analysis shows strong 3<i>d</i> electron localization of Fe³⁺ in FeO₄ tetrahedra, mostly contributing to the high Hubbard energy <i>U</i> in the calculated tetragonal model. Its direct band gap of 2.050 eV is slightly lower than that of the cubic model (2.107 eV) in density of states calculations. The calculated ferrimagnetic ground state exhibits a collinear spin order along the crystallographic <i>c</i> axis in the tetragonal magnetic space group <i>P</i>4₃2₁'2', consistent with the group theoretical prediction. Decreasing ferromagnetic interactions and increasing antiferromagnetic interactions in the <i>c</i> direction, simultaneously, explain the origin of the tetragonality <i>a</i>/<i>c</i> > 1 with <i>a</i> = 8.3528 (2) Å and <i>c</i> = 8.3511 (1) Å. Strong Fe-O-Fe superexchange interactions contribute to the tetragonal lattice distortion of LFO as well.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1307-1318"},"PeriodicalIF":2.8,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A small-angle scattering model for broad correlation peaks and small diffuse scattering.","authors":"Henrich Frielinghaus","doi":"10.1107/S1600576726006825","DOIUrl":"10.1107/S1600576726006825","url":null,"abstract":"<p><p>Porous and/or bicontinuous structures often display a pronounced correlation peak in their small-angle scattering that indicates a preferred domain spacing <i>d</i>. A first attempt to describe the full <i>q</i> dependence of small-angle scattering profiles has been formulated in a previous publication [Frielinghaus (2026) <i>J. Appl. Cryst.</i> <b>59</b>, 837-844]. However, the diffuse scattering, <i>i.e.</i> the forward scattering, is often found to be lower than in this simple framework, while the correlation peak is rather broad. By adding one more parameter σ that stretches the correlation peak with respect to the residual features of the theory, a more general heuristic theoretical framework for porous and/or bicontinuous structures is obtained. The predominant conditions and their physical meaning are discussed in context with practical examples.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1319-1326"},"PeriodicalIF":2.8,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440048/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated analysis with iCM-SANS, SAXS and MD simulations for dynamics of multi-domain proteins.","authors":"Aya Okuda, Rintaro Inoue, Minami Kurokawa, Anne Martel, Lionel Porcar, Rikuto Osaki, Kaori Fukuzawa, Kevin L Weiss, Sai Venkatesh Pingali, Reiko Urade, Masaaki Sugiyama","doi":"10.1107/S1600576726005832","DOIUrl":"10.1107/S1600576726005832","url":null,"abstract":"<p><p>Multi-domain proteins (MDPs) adopt diverse conformations arising from cooperative inter-domain motions, and such dynamics are coupled to their biological functions. Quantitative characterization of these motions is crucial for elucidating their functional mechanisms. Although small-angle X-ray scattering (SAXS) provides information on overall domain arrangement, the limited experimental constraints hinder reliable discrimination of conformational ensembles derived from molecular dynamics (MD) simulations. To address this limitation, complementary experimental constraints that offer domain-selective structural information are required. Inverse contrast-matching small-angle neutron scattering (iCM-SANS), combined with segmental deuteration, enables selective observation of individual domains and provides such complementary constraints. However, practical strategies for preparing segmentally deuterated MDPs have yet to be established. Here, we develop an experimental protocol that integrates controlled protein deuteration with high-efficiency multi-step protein ligation to generate a segmentally deuterated MDP. The combined use of SAXS and iCM-SANS yields complementary structural constraints that enhance discrimination of MD-derived conformational ensembles. This protocol expands the applicability of domain-selective observation, enabling analysis of dynamics in MDPs.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1270-1281"},"PeriodicalIF":2.8,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440049/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A neutron microscope using a nested Wolter-I condenser and a bank of diffractive-refractive achromatic objectives.","authors":"H F Poulsen, C L Andersen, N Ravinet, J Vila-Comamala, M R D Veeraraj, E B Knudsen, P K Willendrup, S Massahi, F E Christensen, D D M Ferreira, M Strobl, C David, L Theil Kuhn","doi":"10.1107/S1600576726006254","DOIUrl":"10.1107/S1600576726006254","url":null,"abstract":"<p><p>We present a nested Wolter-I mirror design for a neutron condenser, which is based on established X-ray telescope technology. We demonstrate through simulations that it can increase the flux density at the ESS imaging instrument ODIN by up to two orders of magnitude. Experimental measurements of reflectivity and figure errors on a prototype mirror element confirm the technical feasibility of the approach. Then, we introduce design strategies for an imaging objective to fully exploit the condenser specifications while achieving spatial resolutions comparable to those of X-ray micro-computed tomography instruments. Analytically, we show that for monochromatic beams suitable solutions exist employing arrays of hundreds of identical objectives, realized either as compound refractive lenses (CRLs) or Fresnel zone plates (FZPs). To mitigate the inherent chromatic aberration of these optics, each individual objective could be replaced by an achromatic FZP/CRL combination. Key optical properties of the resulting microscope are estimated. This novel full-field microscopy concept for highly divergent, polychromatic neutron beams has the potential to improve temporal and spatial resolution for large samples and sample environments and to enable the simultaneous acquisition of hundreds of projections in neutron tomography.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1282-1293"},"PeriodicalIF":2.8,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440045/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-controlled capillary spinner for time-resolved powder X-ray diffraction under dynamic conditions.","authors":"Shogo Kawaguchi, Michitaka Takemoto, Shintaro Kobayashi, Yoshiki Kubota","doi":"10.1107/S160057672600645X","DOIUrl":"10.1107/S160057672600645X","url":null,"abstract":"<p><p>A gas-controlled capillary spinner was developed for time-resolved powder X-ray diffraction measurements of crystalline materials under controlled atmospheres. This system enables continuous sample rotation with simultaneous gas control by integrating a gas-tight capillary cell, a magnetic fluid rotary feedthrough and a fast-response diaphragm valve, allowing diffraction measurements to be performed in rapidly changing environments. The system performance was evaluated using a standard Si powder sample, revealing that high-speed rotation significantly improves the uniformity of the diffraction peak intensity, with relative fluctuations reduced to <1% at speeds of ∼200 r min^-1 even with millisecond-scale measurements. The applicability of the system was demonstrated by time-resolved diffraction measurements of a metal-organic framework during gas adsorption, in which structural changes were successfully tracked and quantitatively analyzed with a time resolution of 50 ms. These findings indicate that the developed system provides a reliable approach for <i>in situ</i> and <i>operando</i> diffraction studies under dynamic gas conditions.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1359-1363"},"PeriodicalIF":2.8,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal expansion of FeWO₄ (ferberite) and FeWO₄:Fe₂WO₆ (7:1): a comparative X-ray and neutron diffraction study.","authors":"O Fabelo, L Cañadillas-Delgado, D Vie, E Matesanz, J Gonzalez-Platas, D Errandonea","doi":"10.1107/S1600576726005297","DOIUrl":"10.1107/S1600576726005297","url":null,"abstract":"<p><p>The thermal expansion of natural FeWO₄ (ferberite) and synthetic FeWO₄:Fe₂WO₆ (7:1) was investigated over the 2-1123 K temperature range, combining single-crystal and powder X-ray diffraction together with neutron powder diffraction. High-precision lattice parameters were obtained for both samples. The temperature dependence of the unit-cell volume was analyzed using physically based thermodynamic models, including the Kroll and Berman approaches as implemented in <i>EoSFit7-GUI</i>. All datasets are well reproduced within their respective temperature intervals. However, significant differences are observed between the behavior of ferberite and FeWO₄:Fe₂WO₆, which has a ∼40% smaller thermal expansion coefficient and a reduced reference volume. The possible origins of these differences, including microstructural and phase-coexistence effects, are discussed. The results provide a comprehensive description of the thermal expansion behavior of FeWO₄ across a wide temperature range.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1238-1246"},"PeriodicalIF":2.8,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440050/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurements and scaling of X-ray total scattering from single crystals.","authors":"Semën Gorfman, Maksim Eremenko, Victor Krayzman, Alexei Bosak, Peter Y Zavalij, Igor Levin","doi":"10.1107/S1600576726006187","DOIUrl":"10.1107/S1600576726006187","url":null,"abstract":"<p><p>This contribution presents a measurement protocol and a data-reduction workflow for obtaining single-crystal X-ray total-scattering datasets that capture both Bragg-peak and diffuse-scattering intensities on an absolute (electrons² per atom) scale. It demonstrates that the intensity scale factor derived from crystallographic refinements using Bragg peaks is in reasonable agreement with the scale obtained by matching the scattering function, computed via spherical integration of the 3D total-scattering signal, to the theoretical coherent baseline. This baseline is calculated from the Debye-Waller factor. The latter scaling approach can be applied to diffuse scattering without including Bragg peaks. These results lay the groundwork for structural refinements using large atomic configurations while simultaneously fitting Bragg intensities and diffuse scattering from a single crystal. Moreover, with the convergence between the two scaling methods, the Bragg and diffuse components can be obtained from the same total-scattering dataset, as achieved in this work, or measured independently.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1224-1237"},"PeriodicalIF":2.8,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440055/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>mmCIF Validator</i>: a comprehensive validation tool for structural biology data files.","authors":"Deborah Harrus, Genevieve L Evans, Sreenath Sasidharan Nair, Weslley Morellato Bueno, Jennifer Fleming, Sameer Velankar","doi":"10.1107/S1600576726005431","DOIUrl":"10.1107/S1600576726005431","url":null,"abstract":"<p><p>The PDBx/macromolecular crystallographic information file (PDBx/mmCIF) framework is the standard for representing macromolecular structure data in the Protein Data Bank (PDB) and has been mandatory for crystallographic depositions since 2019. The PDBx/mmCIF dictionary, maintained by the PDBx/mmCIF working group established by the Worldwide PDB (wwPDB) consortium, defines the schema, data types, enumerations and relationships that govern the structure and content of mmCIFs. Pre-deposition validation of mmCIFs enables researchers to identify and correct errors, ensuring both dictionary compliance and that data values are meaningful and appropriate for their dataset. This validation step can significantly streamline the deposition process in the wwPDB <i>OneDep</i> system, when depositing to the PDB and Electron Microscopy Data Bank archives or using the PDB-IHM deposition system for integrative/hybrid structures, reducing delays and improving data quality. We present the <i>mmCIF Validator</i>, a comprehensive validation tool available in two complementary implementations: a <i>Visual Studio Code</i> extension for real-time interactive validation during file editing; and a standalone Python script for command-line use, batch processing, and integration into automated workflows and CI/CD (continuous integration and continuous delivery/deployment) pipelines. The validator performs comprehensive checks including item-definition validation, mandatory-item presence (with category-aware checking), enumeration-value validation, data-type validation (including automatic regex-based validation extracted from <i>OneDep</i> deposition-specific categories in the dictionary for types like email, phone, ORCID ID and PDB ID), range constraints with distinction between strictly allowed and advisory boundary conditions, parent/child category relationships, foreign-key integrity, composite-key validation for relationships defined by multiple items, duplicate category and item detection, and complex operation-expression parsing. The tool requires Python 3.7+ and uses only the Python standard library (no <i>pip</i> packages required). It works out of the box with automatic dictionary downloading from the official wwPDB repository, or users can employ a custom distant or local dictionary file. The two implementations share the same validation engine, ensuring consistent results across different usage scenarios. The validator is particularly valuable for structural biologists preparing structures for deposition, biocurators ensuring data quality and software developers building automated quality-control workflows.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1338-1343"},"PeriodicalIF":2.8,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grazing-incidence scattering surveyed: towards reference methods for alignment and calibration.","authors":"Anja F Hörmann, Daniel M Balazs, Ingo Breßler, Sumea Klokic, Melika Moradi, Eduardo Solano, Annika Stellhorn, Brian R Pauw","doi":"10.1107/S1600576726005741","DOIUrl":"10.1107/S1600576726005741","url":null,"abstract":"<p><p>Grazing-incidence small-angle scattering (GISAS) is a relatively young technique with important applications in thin-film technology and untapped potential when it comes to 2D analysis on an absolute intensity scale. Approaching standardization and reference methods early is foundational for reproducibility and comparability across laboratories and reduction of systematic error sources. It underpins trust in data obtained and accelerates innovation by ensuring that scientists work from a common methodological baseline. Accordingly, obtaining reproducible results from different GISAS instruments requires an agreement on how measurements are performed, instruments calibrated and terms defined. To pave the way for standardization and reference methods, we surveyed GISAS practitioners on what comes before an experiment: hardware, software, sample alignment and instrument calibration. Twenty-two questions were designed to elucidate the state of the art, which can be used for the development of reference methods. Our data on 27 instruments provide the basis for standardization. With very few exceptions, we found laboratories prepared to implement future reference methods, but no consensus emerges naturally for sample alignment and instrument calibration. We, that is the GISAS community, are thus in a position to embark on the journey of standardization.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1247-1253"},"PeriodicalIF":2.8,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440042/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature evolution of the high-harmonic magnetic modulations in DyFeO₃.","authors":"Piotr Fabrykiewicz, Dnyaneshwar R Bhosale, Martin Meven, Astrid Schneidewind, Karin Schmalzl, Michał Stękiel","doi":"10.1107/S160057672600508X","DOIUrl":"10.1107/S160057672600508X","url":null,"abstract":"<p><p>We report on the temperature evolution of magnetic satellites associated with the incommensurate magnetic ordering of Dy³⁺ ions in DyFeO₃ below 4.1 K. Using high-resolution neutron diffraction, incommensurate magnetic reflections, satellites of the 001 reflection with odd harmonics up to the seventh order, were observed and their temperature dependence quantified. Key parameters, such as the modulation length, FWHM and integrated intensities, were analysed across the measured temperature range. The results were compared with a previous study of the soliton lattice in TbFeO₃ which appears under an applied magnetic field. Possible microscopic models underlying the magnetic order of Dy³⁺ are discussed in this context.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"59 Pt 4","pages":"1332-1337"},"PeriodicalIF":2.8,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}