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Study of the single-crystal X-ray diffuse scattering in paracetamol polymorphs. 扑热息痛多晶单晶x射线散射研究。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-18 DOI: 10.1107/S0108768111046295
E J Chan, D J Goossens
{"title":"Study of the single-crystal X-ray diffuse scattering in paracetamol polymorphs.","authors":"E J Chan,&nbsp;D J Goossens","doi":"10.1107/S0108768111046295","DOIUrl":"https://doi.org/10.1107/S0108768111046295","url":null,"abstract":"<p><p>Single-crystal diffuse X-ray scattering from paracetamol polymorphs is successfully calculated with Monte Carlo (MC) models that are used to simulate the crystals. In order to obtain the correct model appropriate force constants are required that describe the interatomic potentials used in the MC algorithm. Coefficients for an empirical 'Buckingham'-type formula are used to determine these force constants. These coefficients are subsequently refined using the least-squares method and are found to converge on similar values for both polymorphic forms. An investigation of the correlation space generated from each model provides what would be expected given that strong displacive correlations exist between the molecules comprising the densely hydrogen-bonded layers. More disordered motions between these layers are present in the model for form (II) as opposed to form (I). An investigation into the peculiarities of librational disorder was also conducted, however, correlation values turn out to be so small that any structural information concerning librational correlation is inconclusive. The purpose of this experiment was to identify if the diffuse scattering features could provide further insight into understanding the physical reasoning behind the metastability of form (II). The form (II) → (I) phase transition is also not currently well understood and usually phase transitional information can be obtained from pronounced diffuse scattering features. Since the diffuse scattering is modelled adequately using harmonic potentials it is our conjecture that the 'diffuse' is essentially thermal in origin and does not afford any extra information about the form (II) → (I) phase transition.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"80-8"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111046295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30406056","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: 15
Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, γ-Sb2O3, from high-resolution synchrotron powder diffraction data. 基于高分辨率同步加速器粉末衍射数据的一种新型高压高温改性氧化锑γ-Sb2O3的结构
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-18 DOI: 10.1107/S0108768111046751
Denis Orosel, Robert E Dinnebier, Vladislav A Blatov, Martin Jansen
{"title":"Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, γ-Sb2O3, from high-resolution synchrotron powder diffraction data.","authors":"Denis Orosel,&nbsp;Robert E Dinnebier,&nbsp;Vladislav A Blatov,&nbsp;Martin Jansen","doi":"10.1107/S0108768111046751","DOIUrl":"https://doi.org/10.1107/S0108768111046751","url":null,"abstract":"<p><p>A quenchable new high-pressure-high-temperature modification of antimony(III) oxide, γ-Sb(2)O(3), has been obtained at hydrostatic pressures of 9-11 GPa and temperatures of 573-773 K. Its crystal structure has been determined from high-resolution synchrotron powder diffraction data. γ-Sb(2)O(3) consists of three-dimensionally cross-linked infinite chains of SbO(3)E units (E = lone pair) with the chains forming tetragonal rod-packing. The underlying topology of γ-Sb(2)O(3) (3,3T8) is found very rarely in inorganic structures; it is realised only for the polyanion [Si(4)O(4)N(6)](10-) that occurs in the Ce(4)(Si(4)O(4)N(6))O structure type. The structural relation to the two previously known polymorphs of Sb(2)O(3) at ambient pressure, valentinite and senarmontite is discussed.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"1-7"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111046751","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30405030","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: 9
Structural Mineralogy and Inorganic Crystal Chemistry. By Sergey V. Krivovichev. St Petersburg University Press, 2009. Pp. 398. (Hardbound) Price unknown. ISBN 978-5-288-05004-6. 结构矿物学与无机晶体化学。谢尔盖·v·克里沃维切夫著。圣彼得堡大学出版社，2009。398页。(精装版)价格未知。ISBN 978-5-288-05004-6。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 DOI: 10.1107/S010876811105484X
G. Ferraris
{"title":"Structural Mineralogy and Inorganic Crystal Chemistry. By Sergey V. Krivovichev. St Petersburg University Press, 2009. Pp. 398. (Hardbound) Price unknown. ISBN 978-5-288-05004-6.","authors":"G. Ferraris","doi":"10.1107/S010876811105484X","DOIUrl":"https://doi.org/10.1107/S010876811105484X","url":null,"abstract":"This book is devoted to a description of crystal structures of inorganic compounds and, in particular, of minerals, that is, of crystalline substances that constitute the surface and interior of our planet. Understanding their structures is essential for our understanding of the formation and evolution of Earth in geological time. Recently, a new paradigm has emerged that considers minerals as potential advanced materials that can serve as prototypes for the synthesis of new compounds with important technological properties.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"8 1","pages":"98-99"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76025260","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: 6
Structure maps for A(I)4A(II)6(BO4)6X2 apatite compounds via data mining. 通过数据挖掘得到A(I)4A(II)6(BO4)6X2磷灰石化合物的结构图。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-18 DOI: 10.1107/S0108768111054061
Prasanna V Balachandran, Krishna Rajan
{"title":"Structure maps for A(I)4A(II)6(BO4)6X2 apatite compounds via data mining.","authors":"Prasanna V Balachandran,&nbsp;Krishna Rajan","doi":"10.1107/S0108768111054061","DOIUrl":"https://doi.org/10.1107/S0108768111054061","url":null,"abstract":"<p><p>This paper describes a method to identify key crystallographic parameters that can serve as strong classifiers of crystal chemistries and hence define new structure maps. The selection of this pair of key parameters from a large set of potential classifiers is accomplished through a linear data-dimensionality reduction method. A multivariate data set of known A(I)(4)A(II)(6)(BO(4))(6)X(2) apatites is used as the basis for the study where each A(I)(4)A(II)(6)(BO(4))(6)X(2) compound is represented as a 29-dimensional vector, where the vector components are discrete scalar descriptors of electronic and crystal structure attributes. A new structure map, defined using the two distortion angles α(AII) (rotation angle of A(II)-A(II)-A(II) triangular units) and ψ(AIz = 0)(AI-O1) (angle the A(I)-O1 bond makes with the c axis when z = 0 for the A(I) site), is shown to classify apatite crystal chemistries based on site occupancy on the A, B and X sites. The classification is accomplished using a K-means clustering analysis.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"24-33"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111054061","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30406050","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: 21
Polymorphism of Li2Zn3. Li2Zn3的多态性。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-18 DOI: 10.1107/S0108768111053493
Volodymyr Pavlyuk, Ihor Chumak, Helmut Ehrenberg
{"title":"Polymorphism of Li2Zn3.","authors":"Volodymyr Pavlyuk,&nbsp;Ihor Chumak,&nbsp;Helmut Ehrenberg","doi":"10.1107/S0108768111053493","DOIUrl":"https://doi.org/10.1107/S0108768111053493","url":null,"abstract":"<p><p>Crystal structures of low- and high-temperature modifications of the binary phase Li(2)Zn(3) were determined by single-crystal X-ray diffraction techniques. The low-temperature modification is a disordered variant of Li(5)Sn(2), space group Rbar 3m (No. 166). The high-temperature modification crystallizes as an anti-type to Li(5)Ga(4), space group Pbar 3m1 (No. 164). Two polymorphs can be described as derivative structures to binary Li(5)Ga(4), Li(5)Sn(2), Li(13)Sn(5), Li(8)Pb(3), CeCd(2) and CdI(2) phases which belong to class 2 with the parent W-type in Krypyakevich's classification. All atoms in both polymorphs are coordinated by rhombic dodecahedra (coordination number CN = 14) like atoms in related structures. The Li(2)Zn(2.76) (for the low-temperature phase) and Li(2)Zn(2.82) (for the high-temperature phase) compositions were obtained after structure refinements. According to electronic structure calculations using the tight-binding-linear muffin-tin orbital-atomic spheres approximations (TB-LMTO-ASA) method, strong covalent Sn-Sn and Ga-Ga interactions were established in Li(5)Sn(2) and Li(5)Ga(4), but no similar Zn-Zn interactions were observed in Li(2)Zn(3).</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"34-9"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111053493","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30406051","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: 10
Face-to-face stacking of quinoid rings of alkali salts of bromanilic acid. 溴苯甲酸碱盐的类醌环的面对面堆叠。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-06 DOI: 10.1107/S0108768111051159
Krešimir Molčanov, Biserka Kojić-Prodić
{"title":"Face-to-face stacking of quinoid rings of alkali salts of bromanilic acid.","authors":"Krešimir Molčanov,&nbsp;Biserka Kojić-Prodić","doi":"10.1107/S0108768111051159","DOIUrl":"https://doi.org/10.1107/S0108768111051159","url":null,"abstract":"<p><p>A series of alkali salts of hydrogen bromanilic acid trihydrates (K(+), Rb(+) and Cs(+), potassium, rubidium and caesium 2,5-dibromo-4-hydroxy-3,6-dioxocyclohexa-1,4-dien-1-olate trihydrate), bromanilic acid tetrahydrate (Na(+), disodium 2,5-dibromo-3,6-dioxocyclohexa-1,4-diene-1,4-diolate tetrahydrate) and bromanilic acid dihydrates (K(+), Rb(+) and Cs(+), dipotasium, dirubidium and dicaesium 2,5-dibromo-3,6-dioxocyclohexa-1,4-diene-1,4-diolate dihydrate) were prepared and studied by single-crystal X-ray diffraction. Their crystal packings are dominated by quinoid ring stacking. The monoanionic quinoid rings pack face-to-face without offset and with short centroid separations (3.25-3.30 Å), while the dianionic rings form offset stacks (1.4-1.8 Å) with a larger centroid separation (3.8-4.1 Å).</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"57-65"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111051159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30406053","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: 10
Revision of the Mg(ClO4)2·4H2O crystal structure. Mg(ClO4)2·4H2O晶体结构的修正。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 Epub Date: 2012-01-18 DOI: 10.1107/S0108768111054371
Leonid A Solovyov
{"title":"Revision of the Mg(ClO4)2·4H2O crystal structure.","authors":"Leonid A Solovyov","doi":"10.1107/S0108768111054371","DOIUrl":"https://doi.org/10.1107/S0108768111054371","url":null,"abstract":"<p><p>A revision is presented of the restrained Rietveld analysis of the crystal structure of magnesium perchlorate tetrahydrate, Mg(ClO(4))(2)·4H(2)O, recently published by Robertson & Bish [(2010), Acta Cryst. B 66, 579-584]. The actual symmetry of the material is shown to be C2/m. The corrected structure model is refined by the derivative difference method [Solovyov (2004). J. Appl. Cryst. 37, 743-749], anisotropically for all non-H atoms and isotropically for two independent H atoms without restraints.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 1","pages":"89-90"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111054371","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30406057","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: 6
Water channel structure of bassanite at high air humidity: crystal structure of CaSO4·0.625H2O. Corrigendum 高空气湿度下玄武岩的水渠结构:CaSO4·0.625H2O晶体结构。应改正的错误
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2012-02-01 DOI: 10.1107/S0108768111051639
H. Schmidt, Iris Paschke, D. Freyer, W. Voigt
{"title":"Water channel structure of bassanite at high air humidity: crystal structure of CaSO4·0.625H2O. Corrigendum","authors":"H. Schmidt, Iris Paschke, D. Freyer, W. Voigt","doi":"10.1107/S0108768111051639","DOIUrl":"https://doi.org/10.1107/S0108768111051639","url":null,"abstract":"The correspondence author in the paper by Schmidt et al. [(2011), Acta Cryst. B67, 467–475] is corrected.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"360 1","pages":"92-92"},"PeriodicalIF":1.9,"publicationDate":"2012-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75117871","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: 5
Dynamic orientational disorder in crystals of fluoroelpasolites, structural refinement of (NH4)3AlF6, (NH4)3TiOF5 and Rb2KTiOF5. (NH4)3AlF6、(NH4)3TiOF5和Rb2KTiOF5的结构细化。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2011-12-01 Epub Date: 2011-11-17 DOI: 10.1107/S0108768111044867
Anatoly A Udovenko, Natalia M Laptash
{"title":"Dynamic orientational disorder in crystals of fluoroelpasolites, structural refinement of (NH4)3AlF6, (NH4)3TiOF5 and Rb2KTiOF5.","authors":"Anatoly A Udovenko,&nbsp;Natalia M Laptash","doi":"10.1107/S0108768111044867","DOIUrl":"https://doi.org/10.1107/S0108768111044867","url":null,"abstract":"<p><p>Room-temperature crystal structures of triammonium hexafluoroaluminate, (NH(4))(3)AlF(6) (I), and triammonium oxopentafluorotitanate, (NH(4))(3)TiOF(5) (II), were refined, and the crystal structures of dirubidium potassium oxopentaflourotitanate, Rb(2)KTiOF(5), at 297 K (III) and 218 K (IV) were determined using single-crystal X-ray diffraction techniques. In ammonium fluoroelpasolites [(I) and (II)], the ligand (O, F) atoms are located in the mixed 24e + 96j position of the Fm3m unit cell. The 24e position is occupied by the ligand atoms predominantly in (III) and fully in (IV). 'Ordered' N1 and Rb atoms are tetrahedrally displaced from the 8c position into the 32f site, and the H atoms of the disordered ammonium group N2 are statistically distributed in the 96k and 32f positions. The Ti atoms in (II) and (IV) are shifted from the 4a position to 24e thus allowing identification of the O and F atoms in the octahedron on a local scale. The disorder in the crystals is of a dynamic nature. Unique Raman spectra of Rb(2)KTiOF(5) under the laser beam of 1064 nm indicate fast octahedral reorientations resulting in physical equalizations of the Ti-O and Ti-F distances as well as in the appearance of totally synchronous Ti-O and Ti-F stretching vibrations at 750 cm(-1). This phenomenon is assumed to also take place under X-rays.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"67 Pt 6","pages":"447-54"},"PeriodicalIF":1.9,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111044867","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30268303","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: 17
The not so simple cubic structure of PbZr(1-x)Ti(x)O3 (PZT): complex local structural effects in perovskites. PbZr(1-x)Ti(x)O3 (PZT)不简单的立方结构:钙钛矿中复杂的局部结构效应。
IF 1.9 3区 化学
Acta Crystallographica Section B-structural Science Pub Date : 2011-12-01 Epub Date: 2011-11-17 DOI: 10.1107/S010876811103936X
Nan Zhang, Hiroko Yokota, A M Glazer, P A Thomas
{"title":"The not so simple cubic structure of PbZr(1-x)Ti(x)O3 (PZT): complex local structural effects in perovskites.","authors":"Nan Zhang,&nbsp;Hiroko Yokota,&nbsp;A M Glazer,&nbsp;P A Thomas","doi":"10.1107/S010876811103936X","DOIUrl":"https://doi.org/10.1107/S010876811103936X","url":null,"abstract":"<p><p>High-resolution neutron diffraction on the important piezoelectric lead zirconate titanate (PZT) has found that oxygen disorder exists well into the cubic phase. This unexpected result shows that within this phase there persists a remnant of the tilted oxygen octahedra present within the room-temperature ferroelectric phase. The result is that the cubic phase, far from having a simple crystal structure, exhibits a more complex local structure than had hitherto been thought.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"67 Pt 6","pages":"461-6"},"PeriodicalIF":1.9,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S010876811103936X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30269230","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: 23
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