Acta crystallographica Section B, Structural science, crystal engineering and materials最新文献_第2页

Structural and magnetic investigations of the Weyl semimetal family CeAlSi_1-xGe_x. Weyl半金属族CeAlSi1-xGex的结构和磁性研究。

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/S2052520626002635

Daniel A Mayoh, Sanjay Sharma, Thomas W Chamberlain, George D A Wood, Ivan da-Silva, Paul A Goddard, Martin R Lees, Geetha Balakrishnan

{"title":"Structural and magnetic investigations of the Weyl semimetal family CeAlSi1-xGex.","authors":"Daniel A Mayoh, Sanjay Sharma, Thomas W Chamberlain, George D A Wood, Ivan da-Silva, Paul A Goddard, Martin R Lees, Geetha Balakrishnan","doi":"10.1107/S2052520626002635","DOIUrl":"10.1107/S2052520626002635","url":null,"abstract":"We report a systematic study of the structural and magnetic evolution in CeAlSi1-xGex, a series of materials which provide a tunable platform for exploring magnetism in noncentrosymmetric Ce-based intermetallics. Polycrystalline samples and single crystals were synthesized using arc melting and flux growth techniques. Structural characterization by X-ray diffraction shows a continuous increase in the unit-cell parameters with increasing Ge content, with no evidence of a structural phase transition across the series. Magnetization measurements reveal a suppression of the ferromagnetic ordering temperature of CeAlSi with increasing Ge substitution, indicating a crossover toward antiferromagnetic behaviour in Ge-rich compositions. Neutron diffraction measurements performed on selected compositions show that weak magnetic intensity appears on some structural Bragg peaks below the magnetic ordering temperature. These results elucidate the relationship between chemical substitution, crystal structure, and magnetic ground states in CeAlSi1-xGex, and establish this system as a model platform for studying compositionally tuned magnetic order in noncentrosymmetric 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/PMC13238493/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147759592","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

Re-refinement of the structure of the planar hexagonal phase of ZnO nanocrystals. ZnO纳米晶平面六方相结构的再细化。

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/S2052520626003860

Musen Li, Lingyao Zhang, Wei Ren, Jeffrey R Reimers

{"title":"Re-refinement of the structure of the planar hexagonal phase of ZnO nanocrystals.","authors":"Musen Li, Lingyao Zhang, Wei Ren, Jeffrey R Reimers","doi":"10.1107/S2052520626003860","DOIUrl":"10.1107/S2052520626003860","url":null,"abstract":"The planar hexagonal phase of ZnO, known as h-ZnO, g-ZnO, α-ZnO, the Bk structure, the 5-5 phase, the α-BN phase, etc., has P63/mmc symmetry and is implicated in ferroelectric switching mechanisms for wurtzite-ZnO. It is well known in thin films on substrates and can be stabilized by external pressure, but its possible existence is critical in high-purity nanocrystals under ambient conditions. Indeed, a crystal structure has been reported, but this work remains controversial as first-principles calculations predict very different structural properties. Herein, the original experimental data is re-refined, through phase-shift determination and Morlet wavelet transformation, that molecular dynamics simulations associate with a P63/mmc structure with unit-cell parameters at room temperature of a = 3.45±0.02 Å and c = 4.46±0.02 Å. These values are 0.35 Å and 0.80 Å, respectively, larger than those previously reported and in good agreement with computational predictions. This confirms that ZnO nanocrystals can form a metastable planar hexagonal phase. It provides key information pertaining to polarization switching in ZnO, its derivatives, and general wurtzite-structured 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/PMC13238490/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147866346","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

Maus's salts: an old family of iron sulfates with possible magnetic frustration. 鼠氏盐：一个古老的硫酸盐铁家族，可能具有磁性挫败。

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/S2052520626002027

Analeece Long, Matthew Powell, Ashley Dickey, Colin McMillen, Joseph Kolis

{"title":"Maus's salts: an old family of iron sulfates with possible magnetic frustration.","authors":"Analeece Long, Matthew Powell, Ashley Dickey, Colin McMillen, Joseph Kolis","doi":"10.1107/S2052520626002027","DOIUrl":"10.1107/S2052520626002027","url":null,"abstract":"The family of Maus's salts has been known for several centuries, but many aspects of their structures remain elusive, particularly because most examples are highly solvated and readily lose water. To examine the role of alkali cations and water on the structure, and to resolve some ambiguities of previously reported supercells, several new Maus's salt derivatives were synthesized and characterized by low-temperature X-ray diffraction. The parent Maus's salt, K5[Fe3O(SO4)6(H2O)3]·5H2O, grows in hexagonal P63/m, with trigonal symmetry of the Fe3+ clusters, conditions that allow for potential magnetic frustration. A new caesium ferric sulfate complex, Cs5[Fe4O2(HSO4)(SO4)6(H2O)3]·1.75H2O, was also synthesized under the same conditions. It is not a Maus's salt derivative but instead contains Fe3+ tetramers of corner- and edge-sharing iron octahedra, decorated by seven sulfate tetrahedra, crystallizing in monoclinic space group C2/c. Preliminary orientation-dependent magnetic data relative to the trigonal c axis were collected on single crystals of the parent Maus's salt. The data suggests very weak short-range antiferromagnetic spin reorientations with a subtle broad rolling feature having a local maximum near 60-70 K. Magneto-structural anisotropy and spin saturation moments, one-tenth those expected for high-spin Fe3+, suggest a splayed magnetic structure with spin moments predominantly in the trimer plane directed inward about the local z axis toward the shared oxygen between trimers.","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/PMC13238487/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147866375","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

Form (III) of artemisinin: discovery and crystallographic characterization of a new high-pressure polymorph. 青蒿素的形式（III）：一种新的高压多晶型的发现和晶体学表征。

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/S205252062600291X

Banaz Fetah, Lauren E Connor, Mark R Warren, Cheryl L Doherty, Iain D H Oswald

{"title":"Form (III) of artemisinin: discovery and crystallographic characterization of a new high-pressure polymorph.","authors":"Banaz Fetah, Lauren E Connor, Mark R Warren, Cheryl L Doherty, Iain D H Oswald","doi":"10.1107/S205252062600291X","DOIUrl":"10.1107/S205252062600291X","url":null,"abstract":"Artemisinin (ART) is mainly used for the treatment of malaria and exhibits polymorphism with two known crystalline forms. In this study, the high-pressure behaviour of these two polymorphs was investigated to evaluate their compressibility and identify if any pressure-induced phase transitions occur with a view to assessing the impact of manufacturing pressure on the active pharmaceutical ingredient. Form (I), the orthorhombic polymorph, is found to be the most compressible of the three. Form (II), a triclinic phase, undergoes a phase transition to a new polymorph that is observed at different pressures depending on the pressure-transmitting medium (PTM) used. The transition to form (III) occurs at 0.75 GPa when compressed in petroleum ether, however, this transition is delayed to 2.02 GPa in silicone oil. This highlights the influence of the PTM on the stability of the crystal structure. The newly characterized form (III) shares structural similarities with form (II) but differs in symmetry where a pseudo-21 screw axis in form (II) becomes a formal 21 screw axis in form (III), resulting in a change from triclinic to monoclinic and a reduction of the asymmetric unit from Z' = 4 to Z' = 2. These findings contribute to a deeper understanding of pressure-induced polymorphism in ART and underscores the importance of external factors such as PTM in influencing solid-state transitions relevant to pharmaceutical processing and formulation.","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/PMC13238485/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147866348","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

Structural modification of functionalized carbazoles: from Z' = 1 to Z' = 6. 功能化咔唑的结构修饰：从Z' = 1到Z' = 6。

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/S2052520626004506

Matokah Abualnaja, Michael Richard Probert, Michael John Hall, Carolyn P Brock, Paul Gordon Waddell

引用次数: 0

L-threo-D-galacto-Octitol: a curious non-classical order-disorder polytype with an 88 Å axis. l -三-d -半乳糖-辛糖醇：一个奇怪的非经典有序-无序多型，88 Å轴。

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/S2052520626004907

Nina Biedermann, Christoph Standfest, Christian Stanetty, Berthold Stöger, Alexander Virovets, Tobias Wolflehner

{"title":"L-threo-D-galacto-Octitol: a curious non-classical order-disorder polytype with an 88 Å axis.","authors":"Nina Biedermann, Christoph Standfest, Christian Stanetty, Berthold Stöger, Alexander Virovets, Tobias Wolflehner","doi":"10.1107/S2052520626004907","DOIUrl":"10.1107/S2052520626004907","url":null,"abstract":"GalC8 [L-threo-D-galacto-octitol, systematic name (2S,3R,4R,5R,6R,7S)-octane-1,2,3,4,5,6,7,8-octol] crystallizes with a pseudo-tetragonal lattice featuring a long (∼88 Å) c axis. The bulk of the structure possesses P43212 (Z' = 1) pseudo-symmetry, whereby molecules are arranged linearly with eight molecules in a translation period, thus explaining the long c axis. According to this pseudo-symmetry, adjacent molecules are alternately related by 21 screw rotations (in 〈100〉 directions) and twofold rotations (in 〈110〉 directions). Due to an asymmetrical hydrogen-bonding network, symmetry is broken in the vicinity of the twofold rotation axes, leading to an overall P21 (Z' = 4) space-group symmetry. The lost symmetry is retained as a twin operation. The structure can be classified as a `non-classical' OD polytype, in the sense that there are nonequivalent layer contacts, yet all members of the polytype family are locally equivalent. The main polytype is not of a maximum degree of order (MDO) and can be described as an alternation of fragments of the two MDO polytypes with P43 and P212121 symmetry, respectively.","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/PMC13238486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148040686","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

Unraveling the symmetry of Al₅C₃N. 揭开Al5C3N的对称性。

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/S2052520626002544

Vitalii Shtender, Chin Shen Ong, Pedro Berastegui, Olivier Donzel-Gargand, Johan Cedervall, Charles Hervoches, Premek Beran, Olle Eriksson, Ulf Jansson

{"title":"Unraveling the symmetry of Al5C3N.","authors":"Vitalii Shtender, Chin Shen Ong, Pedro Berastegui, Olivier Donzel-Gargand, Johan Cedervall, Charles Hervoches, Premek Beran, Olle Eriksson, Ulf Jansson","doi":"10.1107/S2052520626002544","DOIUrl":"10.1107/S2052520626002544","url":null,"abstract":"High-temperature ceramic compound Al5C3N belongs to the scarcely studied Al-C-N system. It was originally reported as an ordered compound in noncentrosymmetric space group P63mc and described as a nanolaminate with an -Al2C-AlN-Al2C2- stacking sequence. The recently reported structural disorder in the related compound Al4SiC4 led us to question this proposed structure for Al5C3N and investigate the possibility of a disordered structure in the centrosymmetric space group P63/mmc. In the present work, we employed different synthesis routes to maximize the yield and quality of the desired phase, and applied a variety of techniques to probe the Al5C3N crystal structure. Our single-crystal X-ray diffraction analysis clearly indicates that noncentrosymmetric space group P63mc must be rejected. From a joint refinement of single-crystal X-ray and neutron powder diffraction data, the occupancies of C and N were refined at two sites in P63/mmc resulting in the stacking sequence -Al2C-Al(C/N)-Al2(C/N)2-. Furthermore, DFT calculations show that a centrosymmetric disordered structure described in a supercell has the lowest energy, 0.2 eV per formula unit, relative to the previously reported P63mc structure. The calculated band structure shows both direct and indirect bandgaps, which leads to implications for the physical properties. Finally, STEM analysis provides additional evidence that the crystal structure of Al5C3N is better described in centrosymmetric space group P63/mmc.","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/PMC13238491/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147759650","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

Introducing the special issue on current research in crystal growth and related characterization. 介绍了晶体生长及相关表征的研究现状。

IF 1.3 3区化学

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-06-01 DOI: 10.1107/S2052520626004671

Matias Velazquez, Geetha Balakrishnan, Tatyana B Bekker

引用次数: 0

Incommensurate structure of AlPO₄-5 and its stability. AlPO4-5的不匹配结构及其稳定性。

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/S205252062600449X

Kazuki Komatsu, Takuji Ikeda, Tetsuya Kodaira

{"title":"Incommensurate structure of AlPO4-5 and its stability.","authors":"Kazuki Komatsu, Takuji Ikeda, Tetsuya Kodaira","doi":"10.1107/S205252062600449X","DOIUrl":"10.1107/S205252062600449X","url":null,"abstract":"The incommensurate structure of AlPO4-5 and its stability have been investigated in detail. Under ambient conditions, single-crystal X-ray diffraction measurements reveal weak satellite reflections, which become significantly enhanced upon exposure to vacuum. Temperature-dependent X-ray diffraction and Raman scattering measurements of the O-H stretching region show that the appearance of satellite reflections is due to the desorption of water molecules under vacuum, and the satellite reflections disappear above 335 (5) K, whereas their intensity increases again upon cooling to room temperature. To elucidate the origin of the modulation, single-crystal X-ray diffraction experiments were performed on a dehydrated sample. Diffraction data including satellite reflections up to second order were successfully collected, with a modulation vector of q = 0.36710 (5)c*. Analysis of systematic absences up to second-order satellites indicate that the (3+1)D superspace group is P6(00γ)h. On the basis of these data, the first-order positional modulation amplitudes were refined. The results indicate that the modulation originates from correlated rotational displacements of AlO4 and PO4 tetrahedra. This behaviour suggests that phonon-like motions, as proposed in previous studies, persist over a long modulation period and give rise to the observed satellite reflections. These findings highlight a fundamental connection between the intrinsically spatial description of atomic positional modulations in the incommensurate structure and the underlying temporal dynamics.","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/PMC13238488/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148025637","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

AB₂X₄ spinel structures: similarity and differences between the centrosymmetric, Fd3m, and non-centrosymmetric, F4₁32, space groups. AB2X4尖晶石结构：中心对称Fd3m与非中心对称F4132空间群的异同。

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/S2052520626004361

Alla Arakcheeva, Arnaud Magrez, Gervais Chapuis

{"title":"AB2X4 spinel structures: similarity and differences between the centrosymmetric, Fd3m, and non-centrosymmetric, F4132, space groups.","authors":"Alla Arakcheeva, Arnaud Magrez, Gervais Chapuis","doi":"10.1107/S2052520626004361","DOIUrl":"10.1107/S2052520626004361","url":null,"abstract":"Many compounds adopting the spinel AB2X4 structure are technologically important owing to their tunable physical and chemical properties enabling diverse applications in energy storage, catalysis, magnetism, and functional ceramics. Most of them are traditionally assigned to the centrosymmetric space group Fd3m. However, the physical properties of some spinels are incompatible with centrosymmetry. This discrepancy is often accounted for by reducing the symmetry to the non-centrosymmetric space group F43m, allowing thus small atomic displacements from their original position in Fd3m. In this work, we demonstrate that the loss of the inversion symmetry can occur without any atomic displacements, since the centrosymmetric Fd3m and non-centrosymmetric F4132 space groups are equivalent for structure determination and refinement based on X-ray diffraction data. If consistent with experiment, only the use of an anharmonic model of atomic displacements can distinguish these space groups. This study aims to clarify certain misconceptions regarding the structural symmetry and physical properties of spinel-type compounds.","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/PMC13238483/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148052047","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