Acta crystallographica Section B, Structural science, crystal engineering and materials最新文献

High-pressure and high-temperature polymorphism of Na₂CO₃ up to 10 GPa. 高达10 GPa的Na2CO3高压高温多态性。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-23 DOI: 10.1107/S2052520626004956

Benedetta Chrappan Soldavini, Marco Merlini, Chiara Mangano, Davide Comboni, Wilson Crichton, Michael Hanfland

{"title":"High-pressure and high-temperature polymorphism of Na2CO3 up to 10 GPa.","authors":"Benedetta Chrappan Soldavini, Marco Merlini, Chiara Mangano, Davide Comboni, Wilson Crichton, Michael Hanfland","doi":"10.1107/S2052520626004956","DOIUrl":"10.1107/S2052520626004956","url":null,"abstract":"We report two new high-pressure polymorphs of sodium carbonate, ε and ε-II, stable over ∼2 GPa and 11 GPa, respectively. The ε polymorph exhibits a doubling of the c unit-cell parameter relative to the γ and β phases, crystallizes in space group Cc, and has a bulk modulus of 47.6 (8) GPa, comparable to that of the γ phase. Its stability is confirmed using in situ single-crystal and large-volume press (LVP) experiments. Phase transitions observed over a broad pressure-temperature range allow us to refine the topology of the Na2CO3 phase diagram. By integrating precise single-crystal constraints with LVP observations, we propose an updated phase diagram that shows an expanded stability field for the incommensurate γ phase, and reveals a wide stability field for the ε phase at conditions relevant for the Earth's mantle. These results provide improved experimental constraints for the high-pressure behavior of sodium carbonate.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"410-415"},"PeriodicalIF":2.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13470794/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148325061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deciphering unusually large modulations in two related organic hydroxy channel structures. 在两个相关的有机羟基通道结构中破译异常大的调制。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-10 DOI: 10.1107/S2052520626004932

Arie van der Lee, Ioan Stroia, Li Bo Huang, Erol Licsandru, Istvan Kocsis, Mihail Deleanu, Christian Hübschle, Mihail Barboiu, Olivier Pérez

{"title":"Deciphering unusually large modulations in two related organic hydroxy channel structures.","authors":"Arie van der Lee, Ioan Stroia, Li Bo Huang, Erol Licsandru, Istvan Kocsis, Mihail Deleanu, Christian Hübschle, Mihail Barboiu, Olivier Pérez","doi":"10.1107/S2052520626004932","DOIUrl":"10.1107/S2052520626004932","url":null,"abstract":"The incommensurately modulated structures of two related organic hydroxy-channel compounds [(R)-1-(1,3-dihydroxypropan-2-yl)-3-(octan-2-yl)urea, 1; 1-(1,3-dihydroxypropan-2-yl)-3-octylurea, 2] have been determined and compared to the structure of a non-modulated reference compound [(R)-bis-3-(octan-2-yl)urea, 3] lacking hydroxy-channel forming groups. The origin of the modulation is explored through the competition between strong orthogonal urea-urea and hydroxy-hydroxy interactions, though this competition may not be a prerequisite for modulation. Notably, the modulation in these two compounds is unusually pronounced, as shown by the first-order satellite reflections exhibiting intensities comparable to those of the main reflections. This observation is contextualized by comparing the relative intensity differences between main and satellite reflections in a benchmark set of 117 modulated structures. Additionally, an alternative graphical method is introduced to visualize structural modulation within the basic unit cell. This method combines a conventional ball-and-stick representation of the average structure with Lissajous curves that map the spatial modulation onto the unit cell. The curves are color-coded according to the modulation t-parameter, enabling immediate visualization of in-phase and out-of-phase individual modulation displacements.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"375-390"},"PeriodicalIF":2.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13470797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148215966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mapping structure-property relationships in a 6-oxo-verdazyl radical by variable pressure crystallography and density functional theory. 用变压晶体学和密度泛函理论绘制6-氧-绿dazyl自由基的结构-性质关系。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-26 DOI: 10.1107/S2052520626006220

James R Brookes, Varshini J Kumar, Isabelle M Jones, Aston M Summers, Stephanie A Bird, Paul J Low, Stephen A Moggach, Dino Spagnoli

{"title":"Mapping structure-property relationships in a 6-oxo-verdazyl radical by variable pressure crystallography and density functional theory.","authors":"James R Brookes, Varshini J Kumar, Isabelle M Jones, Aston M Summers, Stephanie A Bird, Paul J Low, Stephen A Moggach, Dino Spagnoli","doi":"10.1107/S2052520626006220","DOIUrl":"10.1107/S2052520626006220","url":null,"abstract":"The response of the 1,5-tolyl-3-phenyl-6-oxo-verdazyl radical (pTolOV) to pressure in the crystalline state has been investigated using both high-pressure X-ray diffraction techniques and density functional theory (DFT) calculations. Changes in structure, electronic properties such as band gap and density of states, and magnetic exchange interactions have been explored. Structural analysis reveals a phase transition between the P21/n and C2/c space groups between 2.30 and 2.73 GPa, and an accompanying increase in molecular point group symmetry in the solid state structure at higher pressures. Modelling using periodic DFT-based methods reveals no significant energy penalty to this phase transition with a small reduction in the band gap upon increasing pressure due to changes in the intermolecular distances, before a sharp increase in band gap with the changes in intermolecular alignment in the C2/c phase. These variations fall in the range 2.02-1.94 eV, and the radical remains a wide-gap semiconductor in the solid state across the pressure range examined. Further DFT calculations with gas-phase models reveal weak antiferromagnetic exchange interactions occurring in antiparallel π-stacked chains in both phases.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"416-432"},"PeriodicalIF":2.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13470795/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148337418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Random in-plane translational stacking faults in the van der Waals superlattice Ba₆Nb₁₁Se₂₈. 范德华超晶格Ba6Nb11Se28中的随机面内平移层错。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-10 DOI: 10.1107/S2052520626004737

Ke Ma, Yingpeng Yu, Qi Li, Tianping Ying, Qinghua Zhang, Shifeng Jin, Xiaolong Chen

{"title":"Random in-plane translational stacking faults in the van der Waals superlattice Ba6Nb11Se28.","authors":"Ke Ma, Yingpeng Yu, Qi Li, Tianping Ying, Qinghua Zhang, Shifeng Jin, Xiaolong Chen","doi":"10.1107/S2052520626004737","DOIUrl":"10.1107/S2052520626004737","url":null,"abstract":"The Ba6M11X28 (M = Nb, Ta; X = S, Se) family of natural van der Waals superlattices hosts highly anisotropic superconductivity and exotic two-dimensional electronic behavior. However, the actual stacking sequences of these superconducting superlattices, crucial for property engineering, remains poorly understood. Here we present a detailed microstructural study of Ba6Nb11Se28 using aberration-corrected scanning transmission electron microscopy (STEM), powder X-ray diffraction (PXRD) and DIFFaX simulations. We identify intrinsic in-plane translational stacking faults confined to the Ba3NbSe5 spacer layers and directly resolve three symmetry-equivalent stacking configurations at the atomic scale. These stacking variants preserve the local coordination environment and occur randomly without correlation between adjacent spacer layers. The stacking disorder leads to characteristic extinction of (10l) reflections in diffraction, which is quantitatively reproduced by simulations based on a random stacking model. Our results establish in-plane translational stacking disorder as an intrinsic structural feature of Ba6Nb11Se28 and highlight the importance of spacer-layer degrees of freedom in layered van der Waals superlattices.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"369-374"},"PeriodicalIF":2.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148215947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interaction frequencies as a means to design multicomponent forms. 交互频率作为设计多组件表单的手段。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 DOI: 10.1107/S205252062600795X

Paolo P Mazzeo

引用次数: 0

Thermostructural and elastic properties of Ni₃V₂O₈, exhibiting a kagome layer arrangement: experimental study in the range 15-1323 K. 具有kagome层排列的Ni3V2O8的热结构和弹性性能：15-1323 K范围内的实验研究。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-24 DOI: 10.1107/S2052520626004944

Fiza Aziz, Roman Minikayev, Christine Martin, Henryk Teisseyre, Wojciech Paszkowicz

引用次数: 0

Coupled intra- and inter-tunnel short-range order in hollandites: a case study of mannardite Ba[(Ti⁴⁺)₆(V³⁺)₂]O₁₆. 荷兰岩隧道内和隧道间耦合的短程序：甘菊石Ba[(Ti4+)6(V3+)2]O16的案例研究。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-07-08 DOI: 10.1107/S2052520626006803

Ella Mara Schmidt, Marta Morana, Cristian Biagioni, Arianna Minelli, Alexei Bosak, Giovanni Orazio Lepore

{"title":"Coupled intra- and inter-tunnel short-range order in hollandites: a case study of mannardite Ba[(Ti4+)6(V3+)2]O16.","authors":"Ella Mara Schmidt, Marta Morana, Cristian Biagioni, Arianna Minelli, Alexei Bosak, Giovanni Orazio Lepore","doi":"10.1107/S2052520626006803","DOIUrl":"10.1107/S2052520626006803","url":null,"abstract":"Mannardite, Ba[(Ti4+)6(V3+)2]O16, a mineral of the hollandite supergroup, is characterized by a tunnel structure built up from double chains of edge-sharing octahedra. It shows complex order/disorder phenomena that are often related to the occurrence of diffuse scattering, satellite reflections or both. So far, diffuse scattering features have been linked to ordering of large cations in the tunnel, but recent studies on hollandite sensu stricto suggested that other contributions could play an important role in determining diffuse scattering features. New single-crystal X-ray diffuse scattering data, modelling with Monte Carlo simulations and the three-dimensional difference pair-distribution function (3D-ΔPDF) approach unveil a complex scenario, involving interactions not only between the Ba2+ cations in the tunnel, trying to avoid each other, but also among neighbouring tunnels. Short-range order observed within and between the tunnels is coupled with framework relaxation. The possible occurrence of additional cation sites in the channel, as reported in some synthetic hollandites and electrode materials, is discussed on the basis of the diffuse scattering features and modelling. This study highlights the importance of a thorough characterization of short-range order to understand, and thus tune, the physical properties of hollandite-like materials.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"439-446"},"PeriodicalIF":2.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13470793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148443836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Aurophilic interactions in a mixed-valent Au^I/III 4-cyanothiazole complex. 混价AuI/III 4-氰噻唑配合物中的亲金相互作用。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-07-06 DOI: 10.1107/S2052520626006529

Maciej Ejnik, Łukasz Ponikiewski, Piotr Bruździak, Anna Dołęga

引用次数: 0

Interaction Analysis using the Cambridge Structural Database - rapid access to intermolecular hydrogen-bond frequencies and uses for coformer selection. 使用剑桥结构数据库的相互作用分析-快速获取分子间氢键频率和共变换器选择的用途。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-22 DOI: 10.1107/S2052520626005135

Joanna S Stevens, Andrew G P Maloney, Elna Pidcock

引用次数: 0

Silicon allotropes by large-volume high-pressure techniques: crystal growth mechanisms, phase diagrams and hexagonal nanostructured Si-6H by in situ X-ray diffraction and computational methods. 大体积高压技术制备的硅同素异形体：晶体生长机制、相图和六方纳米Si-6H原位x射线衍射和计算方法。

IF 2.5 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-06-01 DOI: 10.1107/S2052520626004026

Alexandre Courac, Yann Le Godec

{"title":"Silicon allotropes by large-volume high-pressure techniques: crystal growth mechanisms, phase diagrams and hexagonal nanostructured Si-6H by in situ X-ray diffraction and computational methods.","authors":"Alexandre Courac, Yann Le Godec","doi":"10.1107/S2052520626004026","DOIUrl":"10.1107/S2052520626004026","url":null,"abstract":"Metastable allotropes of silicon recovered from high-pressure conditions exhibit a wide range of crystal structures, physical properties and transformation pathways that remain only partially understood despite decades of study. This article combines original crystallographic observations with a critical review of phase transformations, nucleation mechanisms and crystal growth processes in elemental Si and Na-Si systems synthesized under high-pressure, high-temperature conditions. Using in situ diffraction data, structural characterization and computational approaches, we analyze how symmetry breaking, lattice instabilities and kinetic constraints govern the formation of dense polymorphs (Si-II, Si-III, Si-XI) and open-framework structures, including clathrate and channel phases. Particular attention is given to the role of large-volume synthesis and chemically assisted growth routes in controlling phase selection, defect formation and recoverability. The evolution of hexagonal polytypes, including nanostructured 6H silicon, is discussed in terms of stacking modifications driven by stress release and thermal treatment. By integrating crystallographic relations, thermodynamic considerations and growth kinetics, this work identifies phase-transformation mechanisms as the key factor linking structure, synthesis conditions and functional properties of silicon allotropes. The results provide a unified framework for understanding crystal growth at high pressure and offer guidance for the controlled synthesis of advanced silicon materials.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13238484/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148142291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0