Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials最新文献_第3页

X-ray constrained wavefunctions based on Hirshfeld atoms. I. Method and review. 基于Hirshfeld原子的x射线约束波函数。一、方法与回顾。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-31 DOI: 10.1107/s2052520622004097

Max L. Davidson, S. Grabowsky, D. Jayatilaka

引用次数: 0

X-ray constrained wavefunctions based on Hirshfeld atoms. II. Reproducibility of electron densities in crystals of α-oxalic acid dihydrate. 基于Hirshfeld原子的x射线约束波函数。2二水合α-草酸晶体中电子密度的再现性。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-31 DOI: 10.1107/s2052520622004103

Max L. Davidson, S. Grabowsky, D. Jayatilaka

{"title":"X-ray constrained wavefunctions based on Hirshfeld atoms. II. Reproducibility of electron densities in crystals of α-oxalic acid dihydrate.","authors":"Max L. Davidson, S. Grabowsky, D. Jayatilaka","doi":"10.1107/s2052520622004103","DOIUrl":"https://doi.org/10.1107/s2052520622004103","url":null,"abstract":"The Hirshfeld atom-based X-ray constrained wavefunction fitting (HA-XCW) procedure is tested for its reproducibility, and the information content of the fitted wavefunction is critically assessed. Fourteen different α-oxalic acid dihydrate data sets are used for this purpose, and the first joint fitting to 12 of these data sets is reported. There are systematic features in the electron density obtained from all data sets which agree with higher level benchmark calculations, but there are also many other strong systematic features which disagree with the reference calculations, most notably those associated with the electron density near the nuclei. To enhance reproducibility, three new protocols are described and tested to address the halting problem of XCW fitting, namely: an empirical power-function method, which is useful for estimating the accuracy of the structure factor uncertainties; an asymptotic extrapolation method based on ideas from density functional theory; and a `conservative method' whereby the smallest value of the regularization parameter is chosen from a series of data sets, or subsets.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"75 1","pages":"397-415"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76787486","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

Structure correlation and dynamics in crystals - a tribute to Hans-Beat Bürgi. 晶体中的结构相关性和动力学——对汉斯- beat b<s:1> rgi的致敬。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-31 DOI: 10.1107/s2052520622005248

S. Grabowsky, M. Spackman

引用次数: 0

Preliminary observations of the interplay of radiation damage with spin crossover. 辐射损伤与自旋交叉相互作用的初步观察。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-28 DOI: 10.1107/s205252062200467x

D. Chernyshov, V. Dyadkin, K. Törnroos

引用次数: 0

Defects in hafnium-doped lutetium oxide and the corresponding electron traps: a meta-generalized gradient approximation study. 掺铪氧化镥中的缺陷和相应的电子陷阱:一个广义梯度近似研究。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-28 DOI: 10.1107/s205252062200436x

A. Shyichuk, Dagmara Kulesza, E. Zych

{"title":"Defects in hafnium-doped lutetium oxide and the corresponding electron traps: a meta-generalized gradient approximation study.","authors":"A. Shyichuk, Dagmara Kulesza, E. Zych","doi":"10.1107/s205252062200436x","DOIUrl":"https://doi.org/10.1107/s205252062200436x","url":null,"abstract":"A number of Lu2O3-based materials were reported to present efficient capability of trapping excited charge carriers in metastable excited states formed either by specific dopants or naturally occurring defects. Over the years, abundant experimental data have been collected, which were taken as a solid ground to treat the problem using computational chemistry. Density functional theory (DFT) calculations with an advanced meta generalized gradient approximation (mGGA) functional were used to analyze electron trapping in cubic Lu2O3 doped with Hf. Individual ions of dopant and nearest-neighbor dopant ion pairs were considered. The effects of interstitial anions such as O2- and Cl- were analyzed. In most of the analyzed cases the additional electron charge is localized at the dopant site. However, in many of the studied cases, the dopant/defect states overlap with the conduction band and cannot correspond to electron trapping. The Hf3+ ion in the Lu site of C3i local symmetry ({rm Hf}^{times}_{{rm Lu}-C_{rm 3i}}) corresponds to a moderate trap depth of 0.8-0.9 eV. Several composite defects corresponding to deeper (1.1-1.4 eV) traps also exist. Unambiguous deep traps (1.5-1.8 eV) correspond to systems with Hf dopant in the cationic void, accompanied by two interstitial oxygen atoms. The results thus indicate that basic `Hf-substitutes-Lu' doping is unlikely to correspond to the deep traps observed experimentally in Lu2O3:Tb,Hf andLu2O3:Pr,Hf and more complex defects must be involved.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"70 1","pages":"564-575"},"PeriodicalIF":0.0,"publicationDate":"2022-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86122723","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

Solid-state multinuclear magnetic resonance and X-ray crystallographic investigation of the phosphorus...iodine halogen bond in a bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) cocrystal. 磷的固态多核磁共振和x射线晶体学研究。二(双环己基苯基膦)(1,6-二碘过氟己烷)共晶中的碘卤素键。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-28 DOI: 10.1107/s2052520622004322

D. Zheng, Patrick M. J. Szell, Safaa Khiri, Jeffrey S. Ovens, D. L. Bryce

{"title":"Solid-state multinuclear magnetic resonance and X-ray crystallographic investigation of the phosphorus...iodine halogen bond in a bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) cocrystal.","authors":"D. Zheng, Patrick M. J. Szell, Safaa Khiri, Jeffrey S. Ovens, D. L. Bryce","doi":"10.1107/s2052520622004322","DOIUrl":"https://doi.org/10.1107/s2052520622004322","url":null,"abstract":"Halogen bonding to phosphorus atoms remains uncommon, with relatively few examples reported in the literature. Here, the preparation and investigation of the cocrystal bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) by X-ray crystallography and solid-state multinuclear magnetic resonance spectroscopy is described. The crystal structure features two crystallographically unique C-I...P halogen bonds [dI...P = 3.090 (5) Å, 3.264 (5) Å] and crystallographic disorder of one of the 1,6-diiodoperfluorohexane molecules. The first of these is the shortest and most linear I...P halogen bond reported to date. 13C, 19F, and 31P magic angle spinning solid-state NMR spectra are reported. A 31P chemical shift change of -7.0 p.p.m. in the cocrystal relative to pure dicyclohexylphenylphosphine, consistent with halogen bond formation, is noted. This work establishes iodoperfluoroalkanes as viable halogen bond donors when paired with phosphorus acceptors, and also shows that dicyclohexylphenylphosphine can act as a practical halogen bond acceptor.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"23 1","pages":"557-563"},"PeriodicalIF":0.0,"publicationDate":"2022-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90472116","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

Remarks on X-ray constrained/restrained wavefunction fitting. x射线约束/约束波函数拟合评述。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-24 DOI: 10.1107/s2052520622004164

Hans Beat Bürgi, A. Genoni

引用次数: 0

Synthesis and investigation of the thermal properties of [Co(NH3)6][Co(C2O4)3]·3H2O and [Ir(NH3)6][Ir(C2O4)3]. [Co(NH3)6][Co(C2O4)3]·3H2O和[Ir(NH3)6][Ir(C2O4)3]的合成及热性能研究

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-21 DOI: 10.1107/s205252062200405x

E. Filatov, V. Lagunova, Ilia Kochetygov, P. Plyusnin, N. Kuratieva, G. Kostina, S. Koreneva

{"title":"Synthesis and investigation of the thermal properties of [Co(NH3)6][Co(C2O4)3]·3H2O and [Ir(NH3)6][Ir(C2O4)3].","authors":"E. Filatov, V. Lagunova, Ilia Kochetygov, P. Plyusnin, N. Kuratieva, G. Kostina, S. Koreneva","doi":"10.1107/s205252062200405x","DOIUrl":"https://doi.org/10.1107/s205252062200405x","url":null,"abstract":"The complexes [Co(NH3)6][Ir(C2O4)3] and [Ir(NH3)6][Co(C2O4)3]·H2O have previously been synthesized and their thermal properties studied. The [Ir(NH3)6][Ir(C2O4)3] and [Co(NH3)6][Co(C2O4)3]·3H2O complexes considered here are the end members in a series of possible isostructural solid solutions based on the complex salts in the Co-Ir system. Their crystal structures and thermal properties are described in detail, including temperature-dependent in situ X-ray diffraction. During the thermolysis of these compounds, layered metal nanoparticles are formed. Close attention is paid to the details of the [Co(NH3)6][Ir(C2O4)3] synthesis. It has been shown that the formation of this complex salt is temperature dependent; upon heating, a new phase of the K3[Co(NH3)6][Ir(C2O4)3]2·6H2O salt is formed, which incorporates the initial iridium compound into the crystal structure of the double complex salt. The target [Co(NH3)6][Ir(C2O4)3] product is obtained if the synthesis is carried out at room temperature.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"42 1","pages":"537-545"},"PeriodicalIF":0.0,"publicationDate":"2022-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77520491","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

Polymorphic transition due to grinding: the case of 3-[1-(tert-butoxycarbonyl)azetidin-3-yl]-1,2-oxazole-4-carboxylic acid. 研磨引起的多晶转变:以3-[1-(叔丁基羰基)氮杂丁-3-基]-1,2-恶唑-4-羧酸为例。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-21 DOI: 10.1107/s2052520622003900

I. Konovalova, A. Shaposhnyk, V. Baumer, B. Chalyk, S. Shishkina

{"title":"Polymorphic transition due to grinding: the case of 3-[1-(tert-butoxycarbonyl)azetidin-3-yl]-1,2-oxazole-4-carboxylic acid.","authors":"I. Konovalova, A. Shaposhnyk, V. Baumer, B. Chalyk, S. Shishkina","doi":"10.1107/s2052520622003900","DOIUrl":"https://doi.org/10.1107/s2052520622003900","url":null,"abstract":"A polymorphic transition as a result of grinding was found for 3-[1-(tert-butoxycarbonyl)azetidin-3-yl]-1,2-oxazole-4-carboxylic acid. The thorough study of polymorphic structures before and after crystal structure transformation has revealed some pre-conditions for a polymorphic transition and regularities of changes in molecular and crystal structure. In metastable polymorph 1a, the conformationally flexible molecule adopts a conformation with the higher energy and forms a less preferable linear supramolecular synthon. Additional energy imparted to a crystal structure during the grinding process proved to be enough to overcome low energy barriers for the nitrogen inversion and rotation of the oxazole ring around the sp3-sp2 single bond. As a result, polymorph 1b with a molecule adopting conformation with lower energy and forming a more preferable centrosymmetric supramolecular synthon was obtained. The study of pairwise interaction energies in the two polymorphs has shown that metastable polymorph 1a is organized by molecular building units and has a columnar-layered structure. A centrosymmetric dimer should be recognized as a complex building unit in more stable polymorph 1b, which has a layered structure.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"5 1","pages":"510-519"},"PeriodicalIF":0.0,"publicationDate":"2022-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91007689","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

Crystal structure, absolute configuration and characteristic temperatures of SmFe3(BO3)4 in the temperature range 11-400 K. 研究了SmFe3(BO3)4在11 ~ 400 K范围内的晶体结构、绝对构型和特征温度。

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials Pub Date : 2022-05-21 DOI: 10.1107/s2052520622003948

E. Smirnova, O. Alekseeva, A. Dudka, T. Sorokin, D. Khmelenin, V. Yapaskurt, M. Lyubutina, K. Frolov, I. Lyubutin, I. Gudim

{"title":"Crystal structure, absolute configuration and characteristic temperatures of SmFe3(BO3)4 in the temperature range 11-400 K.","authors":"E. Smirnova, O. Alekseeva, A. Dudka, T. Sorokin, D. Khmelenin, V. Yapaskurt, M. Lyubutina, K. Frolov, I. Lyubutin, I. Gudim","doi":"10.1107/s2052520622003948","DOIUrl":"https://doi.org/10.1107/s2052520622003948","url":null,"abstract":"The crystal structure of samarium iron borate was analyzed with regard to growth conditions and temperature. The inclusion of about 7% Bi atoms in the crystals grown using the Bi2Mo3O12-based flux was discovered and there were no impurities in the crystals grown using the Li2WO4-based flux. No pronounced structural features associated with Bi inclusion were observed. The different absolute configurations of the samples grown using both fluxes were demonstrated. Below 80 K, a negative thermal expansion of the c unit-cell parameter was found. The structure of (Sm0.93Bi0.07)Fe3(BO3)4 belongs to the trigonal space group R32 in the temperature range 90-400 K. A decrease in the (Sm,Bi)-O, Sm-B, Sm-Fe, Fe-O, Fe-B and Fe-Fe distances is observed with a lowering of the temperature, B1-O does not change, B2-O increases slightly and the B2O3 triangles deviate from the ab plane. The strongest decrease in the equivalent isotropic atomic displacement parameters (Ueq) with decreasing temperature is observed for atoms Sm and O2, and the weakest is observed for B1. The O2 atoms have the highest Ueq values, the most elongated atomic displacement ellipsoids of all the atoms and the smallest number of allowed vibrational modes of all the O atoms. The largest number of allowed vibrational modes and the strongest interactions with neighbouring atoms is seen for the B atoms, and the opposite is seen for the Sm atoms. The quadrupole splitting Δ(T) of the paramagnetic Mössbauer spectra increases linearly with cooling. The Néel temperature [TN = 31.93 (5) K] was determined from the temperature dependence of the hyperfine magnetic field Bhf(T), which has a non-Brillouin character. The easy-plane long-range magnetic ordering below TN was confirmed.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"190 1","pages":"546-556"},"PeriodicalIF":0.0,"publicationDate":"2022-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74985849","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