Pub Date : 2021-02-01DOI: 10.1107/S2052520620014791
Hao Wu, R. Yu, Jing Zhu, Wei Chen, Yadong Li, Tao Wang
Multiple twinned structures are common in low-dimensional materials. They are intrinsically strained due to the geometrical constraint imposed by the non-crystallographic fivefold symmetry. In this study, the strain distributions in sub-10 nm fivefold twins of gold have been analyzed by combining aberration-corrected transmission electron microscopy and first-principles calculations. Bending of atomic planes has been measured by both experiments and calculations, and its contribution to the filling of the angular gap was shown to be size-dependent.
{"title":"Size-dependent strain in fivefold twins of gold","authors":"Hao Wu, R. Yu, Jing Zhu, Wei Chen, Yadong Li, Tao Wang","doi":"10.1107/S2052520620014791","DOIUrl":"https://doi.org/10.1107/S2052520620014791","url":null,"abstract":"Multiple twinned structures are common in low-dimensional materials. They are intrinsically strained due to the geometrical constraint imposed by the non-crystallographic fivefold symmetry. In this study, the strain distributions in sub-10 nm fivefold twins of gold have been analyzed by combining aberration-corrected transmission electron microscopy and first-principles calculations. Bending of atomic planes has been measured by both experiments and calculations, and its contribution to the filling of the angular gap was shown to be size-dependent.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"19 1","pages":"93-98"},"PeriodicalIF":0.0,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78234891","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}
Pub Date : 2018-02-01DOI: 10.1107/S205252061700498X
S. Aksenov, E. Bykova, R. Rastsvetaeva, N. Chukanov, I. Makarova, M. Hanfland, L. Dubrovinsky
Labuntsovite-Fe, an Fe-dominant member of the labuntsovite subgroup, was first discovered in the Khibiny alkaline massif on Mt Kukisvumchorr [Khomyakov et al. (2001). Zap. Vseross. Mineral. Oba, 130, 36–45]. However, no data are published about the crystal structure of this mineral. Labuntsovite-Fe from a peralkaline pegmatite located on Mt Nyorkpakhk, in the Khibiny alkaline complex, Kola Peninsula, Russia, has been investigated by means of electron microprobe analyses, single-crystal X-ray structure refinement, and IR and Raman spectroscopies. Monoclinic unit-cell parameters of labuntsovite-Fe are: a = 14.2584 (4), b = 13.7541 (6), c = 7.7770 (2) A, β = 116.893 (3)°; V = 1360.22 (9) A3; space group C2/m. The structure was refined to final R1 = 0.0467, wR2 = 0.0715 for 3202 reflections [I > 3σ(I)]. The refined crystal chemical formula is (Z = 2): Na2K2Ba0.7[(Fe0.5Ti0.1Mg0.05)(H2O)1.3]{[Ti2(Ti1.9Nb0.1)(O,OH)4][Si4O12]2}·4H2O. The high-pressure in situ single-crystal X-ray diffraction study of the labuntsovite-Fe has been carried out in a diamond anvil cell. The labuntsovite-type structure is stable up to 23 GPa and phase transitions are not observed. Calculations using the BM3 equation of state resulted in the bulk modulus K = 72 (2) GPa, K′0 = 3.7 (2) and V0 = 1363 (2) A3. Compressing of the heteropolyhedral zeolite-like framework leads to the deformation of main structural units. Octahedral rods show the gradual increase of distortion and the wave-like character of rods becomes more distinct. Rod deformations result in the distortion of the silicon–oxygen ring which is not equal in different directions. Structural channels are characterized by a different ellipticity–pressure relationship: the cross-section of the largest channel I and channel II demonstrates the stability of the geometrical characteristics which practically do not depend on pressure: ∊channel I ≃ 0.85 (4) (cross-section is rather regular) and ∊channel II ≃ 0.52 (2) within the whole pressure range. However, channel III is characterized by the increasing of ellipticity with pressure (∊ = 0.40 → 0.10).
{"title":"Microporous crystal structure of labuntsovite‐Fe and high‐pressure behavior up to 23 GPa","authors":"S. Aksenov, E. Bykova, R. Rastsvetaeva, N. Chukanov, I. Makarova, M. Hanfland, L. Dubrovinsky","doi":"10.1107/S205252061700498X","DOIUrl":"https://doi.org/10.1107/S205252061700498X","url":null,"abstract":"Labuntsovite-Fe, an Fe-dominant member of the labuntsovite subgroup, was first discovered in the Khibiny alkaline massif on Mt Kukisvumchorr [Khomyakov et al. (2001). Zap. Vseross. Mineral. Oba, 130, 36–45]. However, no data are published about the crystal structure of this mineral. Labuntsovite-Fe from a peralkaline pegmatite located on Mt Nyorkpakhk, in the Khibiny alkaline complex, Kola Peninsula, Russia, has been investigated by means of electron microprobe analyses, single-crystal X-ray structure refinement, and IR and Raman spectroscopies. Monoclinic unit-cell parameters of labuntsovite-Fe are: a = 14.2584 (4), b = 13.7541 (6), c = 7.7770 (2) A, β = 116.893 (3)°; V = 1360.22 (9) A3; space group C2/m. The structure was refined to final R1 = 0.0467, wR2 = 0.0715 for 3202 reflections [I > 3σ(I)]. The refined crystal chemical formula is (Z = 2): Na2K2Ba0.7[(Fe0.5Ti0.1Mg0.05)(H2O)1.3]{[Ti2(Ti1.9Nb0.1)(O,OH)4][Si4O12]2}·4H2O. The high-pressure in situ single-crystal X-ray diffraction study of the labuntsovite-Fe has been carried out in a diamond anvil cell. The labuntsovite-type structure is stable up to 23 GPa and phase transitions are not observed. Calculations using the BM3 equation of state resulted in the bulk modulus K = 72 (2) GPa, K′0 = 3.7 (2) and V0 = 1363 (2) A3. Compressing of the heteropolyhedral zeolite-like framework leads to the deformation of main structural units. Octahedral rods show the gradual increase of distortion and the wave-like character of rods becomes more distinct. Rod deformations result in the distortion of the silicon–oxygen ring which is not equal in different directions. Structural channels are characterized by a different ellipticity–pressure relationship: the cross-section of the largest channel I and channel II demonstrates the stability of the geometrical characteristics which practically do not depend on pressure: ∊channel I ≃ 0.85 (4) (cross-section is rather regular) and ∊channel II ≃ 0.52 (2) within the whole pressure range. However, channel III is characterized by the increasing of ellipticity with pressure (∊ = 0.40 → 0.10).","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"53 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78313339","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520617018248
S. Antao, L. Cruickshank
Cubic garnet (space group Iaoverline 3 d) has the general formula X3Y2Z3O12, where X, Y and Z are cation sites. In the tetragonal garnet (space group I41/acd), the corresponding cation sites are X1 and X2, Y, and Z1 and Z2. In both space groups only the Y site is the same. The crystal chemistry of a tetragonal (OH,F)-rich spessartine sample from Tongbei, near Yunxiao, Fujian Province, China, with composition X(Mn2.82Fe^{2+}_{0.14}Ca0.04)Σ3Y{Al1.95Fe^{3+}_{0.05}}Σ2Z[(SiO4)2.61(O4H4)0.28(F4)0.11]Σ3 (Sps94Alm5Grs1) was studied with single-crystal X-ray diffraction and space group I41/acd. The deviation of the unit-cell parameters from cubic symmetry is small [a = 11.64463 (1), c = 11.65481 (2) A, c/a = 1.0009]. Point analyses and back-scattered electron images, obtained by electron-probe microanalysis, indicate a homogeneous composition. The Z2 site is fully occupied, but the Z1 site contains vacancies. The occupied Z1 and Z2 sites with Si atoms are surrounded by four O atoms, as in anhydrous cubic garnets. Pairs of split sites are O1 with F11 and O2 with O22. When the Z1 site is vacant, a larger [(O2H2)F2] tetrahedron is formed by two OH and two F anions in the O22 and F11 sites, respectively. This [(O2H2)F2] tetrahedron is similar to the O4H4 tetrahedron in hydrogarnets. These results indicate ^{X}{{rm Mn}^ {2+}_{3}},^{Y}{rm Al}_{2}^{Z}[({rm SiO}_{4})_{2}({rm O}_{2}{rm H}_{2})_{0.5}({rm F}_{2})_{0.5}]_{Sigma3} as a possible end member, which is yet unknown. The H atom that is bonded to the O22 site is not located because of the small number of OH groups. In contrast, tetragonal henritermierite, ideally ^{X}{rm Ca}_{3},^{Y}{rm Mn}^{3+}_{2},^{Z}[({rm SiO}_{4})_{2}({rm O}_{4}{rm H}_{4})_1]_{Sigma3}, has a vacant Z2 site that contains the O4H4 tetrahedron. The H atom is bonded to an O3 atom [O3—H3 = 0.73 (2) A]. Because of O2—Mn3+—O2 Jahn–Teller elongation of the Mn3+O6 octahedron, a weak hydrogen bond is formed to the under-bonded O2 atom. This causes a large deviation from cubic symmetry (c/a = 0.9534).
{"title":"Crystal structure refinements of tetragonal (OH,F)‐rich spessartine and henritermierite garnets","authors":"S. Antao, L. Cruickshank","doi":"10.1107/S2052520617018248","DOIUrl":"https://doi.org/10.1107/S2052520617018248","url":null,"abstract":"Cubic garnet (space group Iaoverline 3 d) has the general formula X3Y2Z3O12, where X, Y and Z are cation sites. In the tetragonal garnet (space group I41/acd), the corresponding cation sites are X1 and X2, Y, and Z1 and Z2. In both space groups only the Y site is the same. The crystal chemistry of a tetragonal (OH,F)-rich spessartine sample from Tongbei, near Yunxiao, Fujian Province, China, with composition X(Mn2.82Fe^{2+}_{0.14}Ca0.04)Σ3Y{Al1.95Fe^{3+}_{0.05}}Σ2Z[(SiO4)2.61(O4H4)0.28(F4)0.11]Σ3 (Sps94Alm5Grs1) was studied with single-crystal X-ray diffraction and space group I41/acd. The deviation of the unit-cell parameters from cubic symmetry is small [a = 11.64463 (1), c = 11.65481 (2) A, c/a = 1.0009]. Point analyses and back-scattered electron images, obtained by electron-probe microanalysis, indicate a homogeneous composition. The Z2 site is fully occupied, but the Z1 site contains vacancies. The occupied Z1 and Z2 sites with Si atoms are surrounded by four O atoms, as in anhydrous cubic garnets. Pairs of split sites are O1 with F11 and O2 with O22. When the Z1 site is vacant, a larger [(O2H2)F2] tetrahedron is formed by two OH and two F anions in the O22 and F11 sites, respectively. This [(O2H2)F2] tetrahedron is similar to the O4H4 tetrahedron in hydrogarnets. These results indicate ^{X}{{rm Mn}^ {2+}_{3}},^{Y}{rm Al}_{2}^{Z}[({rm SiO}_{4})_{2}({rm O}_{2}{rm H}_{2})_{0.5}({rm F}_{2})_{0.5}]_{Sigma3} as a possible end member, which is yet unknown. The H atom that is bonded to the O22 site is not located because of the small number of OH groups. In contrast, tetragonal henritermierite, ideally ^{X}{rm Ca}_{3},^{Y}{rm Mn}^{3+}_{2},^{Z}[({rm SiO}_{4})_{2}({rm O}_{4}{rm H}_{4})_1]_{Sigma3}, has a vacant Z2 site that contains the O4H4 tetrahedron. The H atom is bonded to an O3 atom [O3—H3 = 0.73 (2) A]. Because of O2—Mn3+—O2 Jahn–Teller elongation of the Mn3+O6 octahedron, a weak hydrogen bond is formed to the under-bonded O2 atom. This causes a large deviation from cubic symmetry (c/a = 0.9534).","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"1991 1","pages":"104-114"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82338981","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520617017425
O. Gagné
Bond-length distributions have been examined for 84 configurations of the lanthanide ions and 22 configurations of the actinide ions bonded to oxygen, for 1317 coordination polyhedra and 10 700 bond distances for the lanthanide ions, and 671 coordination polyhedra and 4754 bond distances for the actinide ions. A linear correlation between mean bond length and coordination number is observed for the trivalent lanthanides ions bonded to O2−. The lanthanide contraction for the trivalent lanthanide ions bonded to O2− is shown to vary as a function of coordination number, and to diminish in scale with an increasing coordination number. The decrease in mean bond length from La3+ to Lu3+ is 0.25 A for coordination number (CN) 6 (9.8%), 0.22 A for CN 7 (8.7%), 0.21 A for CN 8 (8.0%), 0.21 A for CN 9 (8.2%) and 0.18 A for CN 10 (6.9%). The crystal chemistry of Np5+ and Np6+ is shown to be very similar to that of U6+ when bonded to O2−, but differs for Np7+.
{"title":"Bond-length distributions for ions bonded to oxygen: results for the lanthanides and actinides and discussion of the f-block contraction","authors":"O. Gagné","doi":"10.1107/S2052520617017425","DOIUrl":"https://doi.org/10.1107/S2052520617017425","url":null,"abstract":"Bond-length distributions have been examined for 84 configurations of the lanthanide ions and 22 configurations of the actinide ions bonded to oxygen, for 1317 coordination polyhedra and 10 700 bond distances for the lanthanide ions, and 671 coordination polyhedra and 4754 bond distances for the actinide ions. A linear correlation between mean bond length and coordination number is observed for the trivalent lanthanides ions bonded to O2−. The lanthanide contraction for the trivalent lanthanide ions bonded to O2− is shown to vary as a function of coordination number, and to diminish in scale with an increasing coordination number. The decrease in mean bond length from La3+ to Lu3+ is 0.25 A for coordination number (CN) 6 (9.8%), 0.22 A for CN 7 (8.7%), 0.21 A for CN 8 (8.0%), 0.21 A for CN 9 (8.2%) and 0.18 A for CN 10 (6.9%). The crystal chemistry of Np5+ and Np6+ is shown to be very similar to that of U6+ when bonded to O2−, but differs for Np7+.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"75 1","pages":"49-62"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83370002","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520617013038
Sahil Goel, Harsh Yadav, N. Sinha, Budhendra Singh, I. Bdikin, B. Kumar
The 1:1 complex of 8-hydroxyquinoline with squaric acid has been characterized using single-crystal X-ray diffraction, UV–vis spectroscopy, density functional theory (DFT) calculations, and photoluminescence, dielectric, piezoelectric and second-harmonic generation (SHG) studies. The title compound (8-hydroxyquinolinium hydrogen squarate; HQS) contains one protonated 8-hydroxyquinoline cation (C9H8NO+) and one hydrogen squarate mono-anion (C4HO4−). All the intermolecular hydrogen-bonding interactions present in the HQS crystal structure are analyzed by three-dimensional molecular Hirshfeld surface analysis and their relative contributions are determined from two-dimensional fingerprint plots. The structure of C9H8NO+·C4HO4− molecular complex has been optimized at the DFT/B3LYP/6-31G(d,p) level. The UV–vis spectroscopic data calculated by time-dependent density functional theory are compared with the experimental data. The LUMO+1, LUMO, HOMO and HOMO−1 energy values, their shapes and energy gaps are calculated using the B3LYP/6-31G(d,p) level of theory. The HQS material exhibits high SHG output (2.6 times of that of potassium dihydrogen phosphate), high photoluminescence emission centred at 474 nm and a piezoelectric charge coefficient of 3 pC N−1. Henceforth, HQS can serve as an alternative potential candidate for multifunctional nonlinear optically active and piezoelectric crystals.
利用单晶x射线衍射、紫外-可见光谱、密度泛函理论(DFT)计算以及光致发光、介电、压电和二次谐波(SHG)研究对8-羟基喹啉与方酸的1:1配合物进行了表征。标题化合物(8-羟基喹啉氢方;HQS含有一个质子化的8-羟基喹啉阳离子(C9H8NO+)和一个氢方单阴离子(C4HO4−)。通过分子三维Hirshfeld表面分析分析了HQS晶体结构中存在的所有分子间氢键相互作用，并通过二维指纹图谱确定了它们的相对贡献。在DFT/B3LYP/6-31G(d,p)水平上对C9H8NO+·C4HO4−分子配合物的结构进行了优化。用随时间密度泛函理论计算的紫外可见光谱数据与实验数据进行了比较。利用理论的B3LYP/6-31G(d,p)能级计算了LUMO+1、LUMO、HOMO和HOMO−1的能量值、形状和能隙。HQS材料具有高SHG输出(是磷酸二氢钾的2.6倍)、以474 nm为中心的高光致发光发射和3 pC N−1的压电电荷系数。因此，HQS可以作为多功能非线性光学活性和压电晶体的替代候选材料。
{"title":"X‐ray, dielectric, piezoelectric and optical analyses of a new nonlinear optical 8‐hydroxyquinolinium hydrogen squarate crystal","authors":"Sahil Goel, Harsh Yadav, N. Sinha, Budhendra Singh, I. Bdikin, B. Kumar","doi":"10.1107/S2052520617013038","DOIUrl":"https://doi.org/10.1107/S2052520617013038","url":null,"abstract":"The 1:1 complex of 8-hydroxyquinoline with squaric acid has been characterized using single-crystal X-ray diffraction, UV–vis spectroscopy, density functional theory (DFT) calculations, and photoluminescence, dielectric, piezoelectric and second-harmonic generation (SHG) studies. The title compound (8-hydroxyquinolinium hydrogen squarate; HQS) contains one protonated 8-hydroxyquinoline cation (C9H8NO+) and one hydrogen squarate mono-anion (C4HO4−). All the intermolecular hydrogen-bonding interactions present in the HQS crystal structure are analyzed by three-dimensional molecular Hirshfeld surface analysis and their relative contributions are determined from two-dimensional fingerprint plots. The structure of C9H8NO+·C4HO4− molecular complex has been optimized at the DFT/B3LYP/6-31G(d,p) level. The UV–vis spectroscopic data calculated by time-dependent density functional theory are compared with the experimental data. The LUMO+1, LUMO, HOMO and HOMO−1 energy values, their shapes and energy gaps are calculated using the B3LYP/6-31G(d,p) level of theory. The HQS material exhibits high SHG output (2.6 times of that of potassium dihydrogen phosphate), high photoluminescence emission centred at 474 nm and a piezoelectric charge coefficient of 3 pC N−1. Henceforth, HQS can serve as an alternative potential candidate for multifunctional nonlinear optically active and piezoelectric crystals.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"44 1","pages":"12-23"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79700742","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}
Pub Date : 2018-02-01DOI: 10.1107/S205252061701647X
Owen P. Missen, S. Mills, M. Welch, J. Spratt, M. Rumsey, W. Birch, J. Brugger
The crystal structure of cesbronite has been determined using single-crystal X-ray diffraction and supported by electron-microprobe analysis, powder diffraction and Raman spectroscopy. Cesbronite is orthorhombic, space group Cmcm, with a = 2.93172 (16), b = 11.8414 (6), c = 8.6047 (4) A and V = 298.72 (3) A3. The chemical formula of cesbronite has been revised to CuII3TeVIO4(OH)4 from CuII5(TeIVO3)2(OH)6·2H2O. This change has been accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association, Proposal 17-C. The previously reported oxidation state of tellurium has been shown to be incorrect; the crystal structure, bond valence studies and charge balance clearly show tellurium to be hexavalent. The crystal structure of cesbronite is formed from corrugated sheets of edge-sharing CuO6 and (Cu0.5Te0.5)O6 octahedra. The structure determined here is an average structure that has underlying ordering of Cu and Te at one of the two metal sites, designated as M, which has an occupancy Cu0.5Te0.5. This averaging probably arises from an absence of correlation between adjacent polyhedral sheets, as there are two different hydrogen-bonding configurations linking sheets that are related by a ½a offset. Randomised stacking of these two configurations results in the superposition of Cu and Te and leads to the Cu0.5Te0.5 occupancy of the M site in the average structure. Bond-valence analysis is used to choose the most probable Cu/Te ordering scheme and also to identify protonation sites (OH). The chosen ordering scheme and its associated OH sites are shown to be consistent with the revised chemical formula.
采用单晶x射线衍射、电子探针分析、粉末衍射和拉曼光谱等辅助手段对铜铜矿的晶体结构进行了测定。渗铜矿为正交体，空间群为Cmcm, a = 2.93172 (16)， b = 11.8414 (6)， c = 8.6047 (4) a, V = 298.72 (3) A3。铜铜矿的化学式由CuII5(TeIVO3)2(OH)6·2H2O修正为CuII3TeVIO4(OH)4。国际矿物学协会新矿物、命名法和分类委员会提案17-C接受了这一改变。以前报道的碲的氧化态已被证明是不正确的;晶体结构、键价研究和电荷平衡清楚地表明碲是六价的。铜铜矿的晶体结构是由边缘共享的CuO6和(Cu0.5Te0.5)O6八面体的波纹片组成。这里确定的结构是一个平均结构，它在两个金属位点之一具有Cu和Te的潜在顺序，指定为M，其占用率为Cu0.5Te0.5。这种平均可能是由于相邻多面体薄片之间缺乏相关性，因为有两种不同的氢键构型连接薄片，它们之间的偏移量为½a。这两种构型的随机叠加导致Cu和Te的叠加，并导致Cu0.5Te0.5占据平均结构中的M位点。键价分析用于选择最可能的Cu/Te排序方案和确定质子化位点(OH)。所选择的排序方案及其相关的羟基位点与修改后的化学式一致。
{"title":"The crystal structure of cesbronite, Cu3TeO4(OH)4: A novel sheet tellurate topology","authors":"Owen P. Missen, S. Mills, M. Welch, J. Spratt, M. Rumsey, W. Birch, J. Brugger","doi":"10.1107/S205252061701647X","DOIUrl":"https://doi.org/10.1107/S205252061701647X","url":null,"abstract":"The crystal structure of cesbronite has been determined using single-crystal X-ray diffraction and supported by electron-microprobe analysis, powder diffraction and Raman spectroscopy. Cesbronite is orthorhombic, space group Cmcm, with a = 2.93172 (16), b = 11.8414 (6), c = 8.6047 (4) A and V = 298.72 (3) A3. The chemical formula of cesbronite has been revised to CuII3TeVIO4(OH)4 from CuII5(TeIVO3)2(OH)6·2H2O. This change has been accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association, Proposal 17-C. The previously reported oxidation state of tellurium has been shown to be incorrect; the crystal structure, bond valence studies and charge balance clearly show tellurium to be hexavalent. The crystal structure of cesbronite is formed from corrugated sheets of edge-sharing CuO6 and (Cu0.5Te0.5)O6 octahedra. The structure determined here is an average structure that has underlying ordering of Cu and Te at one of the two metal sites, designated as M, which has an occupancy Cu0.5Te0.5. This averaging probably arises from an absence of correlation between adjacent polyhedral sheets, as there are two different hydrogen-bonding configurations linking sheets that are related by a ½a offset. Randomised stacking of these two configurations results in the superposition of Cu and Te and leads to the Cu0.5Te0.5 occupancy of the M site in the average structure. Bond-valence analysis is used to choose the most probable Cu/Te ordering scheme and also to identify protonation sites (OH). The chosen ordering scheme and its associated OH sites are shown to be consistent with the revised chemical formula.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"90 1","pages":"24-31"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89960985","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520617014299
Risha Mishra, Raghavaiah Pallepogu
Co-crystallization experiments conducted between ortho-phenylenediamine (OPDA) and five substituted aromatic acids (phthalic acid, salicylic acid, 4-hydroxybenzoic acid, 4-nitrobenzoic acid and 3,5-dinitrobenzoic acid) reveal the formation of supramolecular networks constructed from acid–base heterosynthons of ortho-phenylenediammonium cations with respective aromatic anions. All of these coformers are generally regarded as safe (GRAS) molecules. The five reported crystal structures are sustained predominantly by intermolecular N+−H⋯O−, N—H⋯O− and N—H⋯O hydrogen-bonding interactions; in addition intramolecular O—H⋯O and intermolecular O—H⋯O, O—H⋯O− and C—H⋯O interactions contribute to the formation of various networks. Five 1:1 salts [NH2C6H4NH3]+·[COOHC6H4COO]− (1); [NH2C6H4NH3]+·[OHC6H4COO]− (2); [{NH2C6H4NH2}2·{OHC6H4COOH}2·{NH2C6H4NH3}+2·{OHC6H4COO}−2] (OPDPHB) (3); [NH2C6H4NH3]+·[NO2C6H4COO]− (4) and [NH2C6H4NH3]+·[(NO2)2C6H4COO]− (5) were isolated as single crystals by the slow evaporation method and were characterized using spectroscopic and X-ray crystallographic techniques. X-ray diffraction studies confirmed the formation of salts. The pKa difference between the amine and respective acid favours the transfer of a proton from the acid to the amine, which leads to the formation of the anion and the cation. The interactions between these ions resulted in a stable heterosynthon in each case. The asymmetric units of salts (1), (2), (4) and (5) contain one anion and one cation each, but salt (3) consists of two anions, two cations and two neutral species in its asymmetric unit. A polymorph of salt (3) was also isolated from the crystallization of the ground material from liquid-assisted grinding [{NH2C6H4NH2}·{NH2C6H4NH3}+·{OHC6H4COO}−] (OPDPHB 3P). The polymorph crystallized in the monoclinic non-centrosymmetric space group P21. The liquid-assisted grinding experiments using a 1:1 ratio also revealed the formation of the expected salts, except salt (3), where this product matches with polymorph (OPDPHB 3P).
{"title":"Supramolecular heterosynthon assemblies of ortho‐phenylenediamine with substituted aromatic carboxylic acids","authors":"Risha Mishra, Raghavaiah Pallepogu","doi":"10.1107/S2052520617014299","DOIUrl":"https://doi.org/10.1107/S2052520617014299","url":null,"abstract":"Co-crystallization experiments conducted between ortho-phenylenediamine (OPDA) and five substituted aromatic acids (phthalic acid, salicylic acid, 4-hydroxybenzoic acid, 4-nitrobenzoic acid and 3,5-dinitrobenzoic acid) reveal the formation of supramolecular networks constructed from acid–base heterosynthons of ortho-phenylenediammonium cations with respective aromatic anions. All of these coformers are generally regarded as safe (GRAS) molecules. The five reported crystal structures are sustained predominantly by intermolecular N+−H⋯O−, N—H⋯O− and N—H⋯O hydrogen-bonding interactions; in addition intramolecular O—H⋯O and intermolecular O—H⋯O, O—H⋯O− and C—H⋯O interactions contribute to the formation of various networks. Five 1:1 salts [NH2C6H4NH3]+·[COOHC6H4COO]− (1); [NH2C6H4NH3]+·[OHC6H4COO]− (2); [{NH2C6H4NH2}2·{OHC6H4COOH}2·{NH2C6H4NH3}+2·{OHC6H4COO}−2] (OPDPHB) (3); [NH2C6H4NH3]+·[NO2C6H4COO]− (4) and [NH2C6H4NH3]+·[(NO2)2C6H4COO]− (5) were isolated as single crystals by the slow evaporation method and were characterized using spectroscopic and X-ray crystallographic techniques. X-ray diffraction studies confirmed the formation of salts. The pKa difference between the amine and respective acid favours the transfer of a proton from the acid to the amine, which leads to the formation of the anion and the cation. The interactions between these ions resulted in a stable heterosynthon in each case. The asymmetric units of salts (1), (2), (4) and (5) contain one anion and one cation each, but salt (3) consists of two anions, two cations and two neutral species in its asymmetric unit. A polymorph of salt (3) was also isolated from the crystallization of the ground material from liquid-assisted grinding [{NH2C6H4NH2}·{NH2C6H4NH3}+·{OHC6H4COO}−] (OPDPHB 3P). The polymorph crystallized in the monoclinic non-centrosymmetric space group P21. The liquid-assisted grinding experiments using a 1:1 ratio also revealed the formation of the expected salts, except salt (3), where this product matches with polymorph (OPDPHB 3P).","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"44 1","pages":"32-41"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86754539","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520618001154
F. Faure
The second edition is a true introduction to mineralogy and petrology. The book encompasses the fundamental aspects of mineralogy, crystallography, thermodynamics and kinetics; it presents also their related instrumental methods and which processes are involved in the formation of rocks, that is, in essence, petrology. The book is organized in such a way that any new student or researcher to the field can rapidly acquire a lot of knowledge on the main concepts of petrology. Each chapter begins with a brief abstract and at the end includes a quiz to allow the reader to evaluate if they have understood the main concepts presented. Each chapter contains links to Web sites offering software programs, animations and images of rocks samples (hand specimens and thin sections). Each chapter ends with references for further reading material for a deeper coverage of the subject. An index and a glossary are given at the end of the book for additional references. This textbook will allow the reader to acquire in a course semester all the basic information needed to describe and understand how rocks form. The background developed in the early chapters (on crystal structures, crystallography, how to used a petrographic microscope . . . ) is dense but the explanations are clear and well illustrated. The authors chose to present the systematic mineralogical description simultaneously with the type of rocks in which these minerals occur. I think that this is a very good idea: by doing so, it will show to the student that in petrology only a limited number of minerals need to be known. The addition of a new chapter (dedicated to thermodynamics and kinetics processes) that did not appear in the first edition will allow the students to understand more the processes involved in the formation of rocks, and how to determine their ages. This new chapter will be fundamental by providing a global view on petrology. The uses of minerals in commercial applications are outlined throughout the book, and even the penultimate chapter focuses on some selected examples of Earth material resources that are used in everyday life. Finally, the last chapter discusses the beneficial and negative effects these Earth materials can have on human health. Another strength of the book is the high quality of its color illustrations. The photographs in the field, of hand specimens and thin sections are all beautiful and useful. Overall, I highly recommend this book. By using this book, a student will become rapidly familiar with the discipline by acquiring the majority of skills needed to investigate a wide range of rocks. ISSN 2052-5206
{"title":"Earth Materials. Introduction to Mineralogy and Petrology. 2nd edition. By Cornelis Klein and Anthony Philpotts. Cambridge University Press, 2016. Pp. 616. Price GBP 49.99 (ISBN 9781316608852, paperback), GBP 100 (ISBN 9781107155404, hardcover)","authors":"F. Faure","doi":"10.1107/S2052520618001154","DOIUrl":"https://doi.org/10.1107/S2052520618001154","url":null,"abstract":"The second edition is a true introduction to mineralogy and petrology. The book encompasses the fundamental aspects of mineralogy, crystallography, thermodynamics and kinetics; it presents also their related instrumental methods and which processes are involved in the formation of rocks, that is, in essence, petrology. The book is organized in such a way that any new student or researcher to the field can rapidly acquire a lot of knowledge on the main concepts of petrology. Each chapter begins with a brief abstract and at the end includes a quiz to allow the reader to evaluate if they have understood the main concepts presented. Each chapter contains links to Web sites offering software programs, animations and images of rocks samples (hand specimens and thin sections). Each chapter ends with references for further reading material for a deeper coverage of the subject. An index and a glossary are given at the end of the book for additional references. This textbook will allow the reader to acquire in a course semester all the basic information needed to describe and understand how rocks form. The background developed in the early chapters (on crystal structures, crystallography, how to used a petrographic microscope . . . ) is dense but the explanations are clear and well illustrated. The authors chose to present the systematic mineralogical description simultaneously with the type of rocks in which these minerals occur. I think that this is a very good idea: by doing so, it will show to the student that in petrology only a limited number of minerals need to be known. The addition of a new chapter (dedicated to thermodynamics and kinetics processes) that did not appear in the first edition will allow the students to understand more the processes involved in the formation of rocks, and how to determine their ages. This new chapter will be fundamental by providing a global view on petrology. The uses of minerals in commercial applications are outlined throughout the book, and even the penultimate chapter focuses on some selected examples of Earth material resources that are used in everyday life. Finally, the last chapter discusses the beneficial and negative effects these Earth materials can have on human health. Another strength of the book is the high quality of its color illustrations. The photographs in the field, of hand specimens and thin sections are all beautiful and useful. Overall, I highly recommend this book. By using this book, a student will become rapidly familiar with the discipline by acquiring the majority of skills needed to investigate a wide range of rocks. ISSN 2052-5206","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"79 1","pages":"121-121"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74432837","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}
Pub Date : 2018-02-01DOI: 10.1107/S2052520617017371
M. D. Perera, A. S. Sinha, C. Aakeröy
The importance of using structural mimics for mapping out the structural landscape of a poorly soluble active pharmaceutical ingredient was investigated using erlotinib as an example. A mimic was synthesized by preserving the main molecular functionalities responsible for creating the most probable structural arrangements in the solid state. Calculated molecular electrostatic potentials on both erlotinib and the mimic showed very comparable values indicating that the latter would be able to form hydrogen bonds of similar probability and strength as those of erlotinib. In order to establish the binding preference in co-crystallization experiments, the mimic molecule was co-crystallized with US Food and Drug Administration approved dicarboxylic acids. The crystal structures of the mimic and of four co-crystals thereof were obtained. The mimic forms hydrogen bonds in a way that closely resembles those found in the crystal structure of erlotinib. The four co-crystals display self-consistent hydrogen-bond interactions. Thermal and solubility data for the co-crystals demonstrate that by making systematic and controllable changes to the solid forms of the mimic, it is also possible to alter the behaviour and properties of the new solid forms. The use of a suitable structural mimic can allow for a systematic structural examination of a compound that is otherwise not amenable to such investigations by facilitating the elucidation and mapping out of a closely related structural landscape.
{"title":"Using structural mimics for accessing and exploring structural landscapes of poorly soluble molecular solids","authors":"M. D. Perera, A. S. Sinha, C. Aakeröy","doi":"10.1107/S2052520617017371","DOIUrl":"https://doi.org/10.1107/S2052520617017371","url":null,"abstract":"The importance of using structural mimics for mapping out the structural landscape of a poorly soluble active pharmaceutical ingredient was investigated using erlotinib as an example. A mimic was synthesized by preserving the main molecular functionalities responsible for creating the most probable structural arrangements in the solid state. Calculated molecular electrostatic potentials on both erlotinib and the mimic showed very comparable values indicating that the latter would be able to form hydrogen bonds of similar probability and strength as those of erlotinib. In order to establish the binding preference in co-crystallization experiments, the mimic molecule was co-crystallized with US Food and Drug Administration approved dicarboxylic acids. The crystal structures of the mimic and of four co-crystals thereof were obtained. The mimic forms hydrogen bonds in a way that closely resembles those found in the crystal structure of erlotinib. The four co-crystals display self-consistent hydrogen-bond interactions. Thermal and solubility data for the co-crystals demonstrate that by making systematic and controllable changes to the solid forms of the mimic, it is also possible to alter the behaviour and properties of the new solid forms. The use of a suitable structural mimic can allow for a systematic structural examination of a compound that is otherwise not amenable to such investigations by facilitating the elucidation and mapping out of a closely related structural landscape.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"124 1","pages":"42-48"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85708568","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}
Pub Date : 2018-02-01DOI: 10.1107/S205252061701811X
O. Yakubovich, O. Yakubovich, O. Yakubovich, L. Shvanskaya, L. Shvanskaya, Z. Pchelkina, O. Dimitrova, A. Volkov, O. Volkova, O. Volkova, O. Volkova, A. Vasiliev, A. Vasiliev, A. Vasiliev
Potassium dimanganese trivanadate, KMn2V3O10, was synthesized hydrothermally and its crystal structure was determined from single-crystal X-ray diffraction data. The novel phase crystallizes with triclinic symmetry in space group Pbar 1 with unit-cell parameters of a = 6.912 (5), b = 6.993 (5), c = 9.656 (5) A, α = 101.858 (5), β = 102.627 (5), γ = 100.669 (5)°, Z = 2 and V = 432.6 (5) A3. Its structure is built from tetramers of MnO6 octahedra sharing edges and trimers of VO4 tetrahedra sharing vertices. These main structural fragments are linked in a three-dimensional framework with channels occupied by potassium ions. The transformation of this structure to that of interconnected NaCa3Mn(V3O10)(V2O7) is discussed. The title compound orders antiferromagnetically at TN = 8.2 K due to the magnetic exchange interactions between tetramers of Mn octahedra through VO4 tetrahedra. First-principles calculations show the magnetic couplings via Mn—O—Mn and Mn—O—V—O—Mn pathways.
{"title":"A novel representative in the rare family of trivanadates, KMn2V3O10: synthesis, crystal structure and magnetic properties","authors":"O. Yakubovich, O. Yakubovich, O. Yakubovich, L. Shvanskaya, L. Shvanskaya, Z. Pchelkina, O. Dimitrova, A. Volkov, O. Volkova, O. Volkova, O. Volkova, A. Vasiliev, A. Vasiliev, A. Vasiliev","doi":"10.1107/S205252061701811X","DOIUrl":"https://doi.org/10.1107/S205252061701811X","url":null,"abstract":"Potassium dimanganese trivanadate, KMn2V3O10, was synthesized hydrothermally and its crystal structure was determined from single-crystal X-ray diffraction data. The novel phase crystallizes with triclinic symmetry in space group Pbar 1 with unit-cell parameters of a = 6.912 (5), b = 6.993 (5), c = 9.656 (5) A, α = 101.858 (5), β = 102.627 (5), γ = 100.669 (5)°, Z = 2 and V = 432.6 (5) A3. Its structure is built from tetramers of MnO6 octahedra sharing edges and trimers of VO4 tetrahedra sharing vertices. These main structural fragments are linked in a three-dimensional framework with channels occupied by potassium ions. The transformation of this structure to that of interconnected NaCa3Mn(V3O10)(V2O7) is discussed. The title compound orders antiferromagnetically at TN = 8.2 K due to the magnetic exchange interactions between tetramers of Mn octahedra through VO4 tetrahedra. First-principles calculations show the magnetic couplings via Mn—O—Mn and Mn—O—V—O—Mn pathways.","PeriodicalId":6887,"journal":{"name":"Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry","volume":"13 1","pages":"97-103"},"PeriodicalIF":0.0,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89907007","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}
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