Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials最新文献_第6页

Compressibility of structural modulation waves in the chain compounds BaCoX2O7 (X = As, P): a powder study. 链状化合物BaCoX2O7 (X = As, P)结构调制波的可压缩性:粉末研究。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-03-15 DOI: 10.1107/s2052520622001159

Ranjana‐Rani Das, Bastien Leclercq, P. Bouvier, Á. Arévalo-López, C. Goujon, J. Itié, A. Polian, O. Mentré, C. Colin

{"title":"Compressibility of structural modulation waves in the chain compounds BaCoX2O7 (X = As, P): a powder study.","authors":"Ranjana‐Rani Das, Bastien Leclercq, P. Bouvier, Á. Arévalo-López, C. Goujon, J. Itié, A. Polian, O. Mentré, C. Colin","doi":"10.1107/s2052520622001159","DOIUrl":"https://doi.org/10.1107/s2052520622001159","url":null,"abstract":"BaCoX2O7 (X = As, P) are built on magnetic 1D units in which strong aperiodic undulations originate from incommensurate structural modulations with large atomic displacive amplitudes perpendicular to the chain directions, resulting in very unique multiferroic properties. High-pressure structural and vibrational properties of both compounds have been investigated by synchrotron X-ray powder diffraction and Raman spectroscopy at room temperature and combined with density functional calculations. A structural phase transition is observed at 1.8 GPa and 6.8 GPa in BaCoAs2O7 and BaCoP2O7, respectively. Sharp jumps are observed in their unit-cell volumes and in Raman mode frequencies, thus confirming the first-order nature of their phase transition. These transitions involve the disappearance of the modulation from the ambient-pressure polymorph with clear spectroscopic fingerprints, such as reduction of the number of Raman modes and change of shape on some peaks. The relation between the evolution of the Raman modes along with the structure are presented and supported by density functional theory structural relaxations.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"16 1","pages":"162-171"},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75238779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphotropism in fumarolic mineral-related anhydrous sulfates: novel representatives in A+2M2+(SO4)2 and A+2M2+2(SO4)3 series. 富马酚类矿物相关无水硫酸盐的形态向性:A+2M2+(SO4)2和A+2M2+2(SO4)3系列的新代表。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-03-12 DOI: 10.1107/s2052520622000919

O. Siidra, Diana Nekrasova, O. Blatova, M. Colmont, O. Mentré, D. Charkin

引用次数: 0

Structure of the high-temperature phase of caesium nitrate - the importance of high-resolution data. 硝酸铯高温相的结构-高分辨率数据的重要性。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-03-10 DOI: 10.1107/s2052520622001135

J. Fábry, M. Kučeráková, M. Dušek, E. Buixaderas, J. Hlinka

引用次数: 0

Temperature-dependent crystal structure investigation of 4f hybridized thermoelectric clathrate Ba8-xCexAuySi46-y. 4f杂化热电包合物Ba8-xCexAuySi46-y的温度依赖性晶体结构研究。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-22 DOI: 10.1107/s205252062101310x

J. Sandemann, Hazel Reardon, B. Brummerstedt Iversen

{"title":"Temperature-dependent crystal structure investigation of 4f hybridized thermoelectric clathrate Ba8-xCexAuySi46-y.","authors":"J. Sandemann, Hazel Reardon, B. Brummerstedt Iversen","doi":"10.1107/s205252062101310x","DOIUrl":"https://doi.org/10.1107/s205252062101310x","url":null,"abstract":"Thermoelectric materials allow for conversion of waste heat into electrical energy, and they represent a green solution for improving our energy efficiency. Inclusion of 4f electrons near the Fermi level may boost the Seebeck coefficient, which is essential for high thermoelectric performance. In this study, Ce was successfully substituted for Ba on the guest atom sites in the type-I clathrate Ba8-xCexAuySi46-y and the material was characterized using high-resolution synchrotron powder X-ray diffraction data measured from 100 K to 1000 K to investigate potential structural implications of the inclusion of a 4f element. The thermal expansion and bonding of the host structure are not affected by the presence of Ce, as seen from the linear coefficient of unit-cell thermal expansion of 7.30 (8) × 10-6 K-1 and the average host Debye temperature of 404 (7) K determined from the multi-temperature atomic displacement parameters, both of which are similar to values obtained for pure Ba8AuySi46-y. The anisotropic atomic displacement parameters on the guest atom site in the large clathrate cage populated by Ba surprisingly reveals isotropic behavior, which is different from all other clathrates reported in literature, and thus represents a unique host-guest bonding situation.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"4 1","pages":"359-368"},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86040806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Collaboration with Hans-Beat Bürgi: crystallography at Bern and Lausanne. 与Hans-Beat b<s:1> rgi:晶体学在伯尔尼和洛桑的合作。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-21 DOI: 10.1107/s2052520622000646

D. Schwarzenbach

引用次数: 0

A novel energetic cocrystal composed of CL-20 and 1-methyl-2,4,5-trinitroimidazole with high energy and low sensitivity. 由CL-20和1-甲基-2,4,5-三硝基咪唑组成的高能量低灵敏度新型高能共晶。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-19 DOI: 10.1107/s2052520622000245

P. Lian, L. Zhang, Hongping Su, Jun Chen, Lizhen Chen, Jianlong Wang

引用次数: 1

Obtaining diffuse scattering patterns from computer simulations - a retrospective. 从计算机模拟中获得漫射散射模式——回顾。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-18 DOI: 10.1107/s2052520621012865

T. Welberry

引用次数: 0

Mesocrystalline structure and mechanical properties of biogenic calcite from sea urchin spine. 海胆脊椎生物源方解石的介晶结构及力学性能。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-18 DOI: 10.1107/s2052520622000634

H. Cölfen, H. Bürgi, D. Chernyshov, M. Stekiel, A. Chumakova, A. Bosak, B. Wehinger, B. Winkler

引用次数: 0

Dynamic simulation of orientational disorder in organic crystals: methyl groups, trifluoromethyl groups and whole molecules. 有机晶体中定向紊乱的动态模拟:甲基、三氟甲基和整个分子。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-18 DOI: 10.1107/s2052520621012191

A. Gavezzotti

{"title":"Dynamic simulation of orientational disorder in organic crystals: methyl groups, trifluoromethyl groups and whole molecules.","authors":"A. Gavezzotti","doi":"10.1107/s2052520621012191","DOIUrl":"https://doi.org/10.1107/s2052520621012191","url":null,"abstract":"Large amplitude librations of atomic groups or of entire molecules in their crystals are simulated using optimized intermolecular potentials and crystal structures deposited in the Cambridge Structural Database. The analysis proceeds by a simple static model in which reorientations take place in a fixed environment, or by Monte Carlo (MC) simulation of equilibria dotted by rotational defects, or eventually by full Molecular Dynamics (MD). The simplest approach provides a valuable qualitative preview, but MC and MD are becoming easily accessible to the general solid-state chemist thanks to the facilities of the newly developed Milano Chemistry Molecular Simulation (MiCMoS) platform. Their combined results offer a wealth of information on the behaviour of phenyl-methyl and phenyl-trifluoromethyl groups, almost invariably affected by rotational flipping, whose nature and consequences are discussed with respect to disorder modelling in the refinement of X-ray structures. Whole-body reorientation takes place in flat molecules, benzene being the well-known prototype, but also in a very large molecule like coronene. Molecular dynamics of rotations in the cyclohexa-1,4-diene crystal offer a spectacular picture of the energetic profiles with jumping times. The dynamic oscillations described here are seldom considered in the formulation of crystal `bonds' or of `synthon' stability.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"11 5-6 1","pages":"333-343"},"PeriodicalIF":0.0,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75237806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Rearrangements in the multiverse. 多重宇宙中的重排。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-02-18 DOI: 10.1107/s2052520622000592

R. Hoffmann

引用次数: 0