Mapping structural correlations in real space
(Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - March 27, 2023 Category: Chemistry Authors: Osborn, R. Tags: structural correlations real space scientific commentaries Source Type: research
How much do molecular shapes matter?
(Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - March 25, 2023 Category: Chemistry Authors: Bhadbhade, M. Tags: polymorphism nifedipine solvate pharmaceutical scientific commentaries Source Type: research
Analytic description of nanowires II: morphing of regular cross sections for zincblende- and diamond-structures to match arbitrary shapes. Corrigendum
Corrections to the article by K ö nig and Smith [Acta Cryst. (2022), B78, 643 – 664] are given. (Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - March 14, 2023 Category: Chemistry Authors: K ö nig, D. Smith, S.C. Tags: nanowire cross section metrology morphing zincblende diamond addenda and errata Source Type: research
Refinement of the crystal structure of fresnoite, Ba2TiSi2O8, from L ö hley (Eifel district, Germany); Gladstone – Dale compatibility, electronic polarizability and vibrational spectroscopy of minerals and inorganic compounds with pentacoordinated TiIV and a titanyl bond
Most known compounds with five-coordinated Ti4+ are natural and synthetic titanosilicates. The crystal structure of natural fresnoite, Ba2TiSi2O8 [tetragonal, space group P4bm, a = 8.510 (1) Å , c = 5.197 (1) Å , V = 376.4 (1) Å 3, Z = 2], has been refined to R = 0.011 on the basis of 807 unique single-crystal reflections with I> 2 σ (I). Titanium has fivefold coordination with one short (`titanyl') bond of 1.692 (5) Å . Bonds in the TiO5 polyhedron are discussed in comparison to analogous coordination polyhedra in other minerals and compounds. A review of all known compounds with Ti4+O...
Source: Acta Crystallographica Section B - March 9, 2023 Category: Chemistry Authors: Chukanov, N.V. Kazheva, O.N. Fischer, R.X. Aksenov, S.M. Tags: fresnoite titanyl bond pentacoordinated titanium electronic polarization optical properties research papers Source Type: research
Polytypism of Ln(SeO3)(HSeO3) · 2H2O compounds: synthesis and crystal structure of the first monoclinic modification of Nd(SeO3)(HSeO3) · 2H2O, DFT calculations and order/disorder description
Compounds with the general formula Ln3+(SeO3)(HSeO3) · 2H2O, where Ln = Sm3+, Tb3+, Nd3+ and Lu3+, are characterized by orthorhombic symmetry with space group P212121 and unit-cell parameters in the ranges a ∼ 6.473 – 6.999, b ∼ 6.845 – 7.101, c ∼ 16.242 – 16.426 Å . Light-purple irregularly shaped crystals of a new monoclinic polytype of neodymium selenite Nd(SeO3)(HSeO3) · 2H2O have been obtained during a mild-condition hydrothermal synthesis. The monoclinic unit-cell parameters are: a = 7.0815 (2), b = 6.6996 (2), c = 16.7734 (5) Å , β = 101.256 (1) ° , V = 780.48 (6) Å...
Source: Acta Crystallographica Section B - March 9, 2023 Category: Chemistry Authors: Murtazoev, A.F. Berdonosov, P.S. Aksenov, S.M. Kuznetsov, A.E. Dolgikh, V.A. Nelyubina, Y.V. Merlino, S. Tags: order – disorder structures polytypism selenites rare-earth modularity research papers Source Type: research
Exploring the thermal behaviour of the solvated structures of nifedipine
In this study, the isolation and characterization of seven solvates of the L-type calcium channel antagonist, nifedipine, is described using variable-temperature powder X-ray diffraction so that the structural evolution as a function of temperature can be followed. The solvates reported herein can be split into those that are structurally similar to the previously reported dimethyl sulfoxide (DMSO) and dioxane solvates and those that have a novel packing arrangement. Of particular note is the solvate with tetrahydrofuran (THF) which has a hydrogen-bonding motif between the nifedipine molecules very similar to that of metas...
Source: Acta Crystallographica Section B - March 9, 2023 Category: Chemistry Authors: Jones, E.C.L. Goldsmith, K.E. Ward, M.R. Bimbo, L.M. Oswald, I.D.H. Tags: solvate desolvation nifedipine pharmaceutical variable-temperature X-ray diffraction research papers Source Type: research
Structural and magnetic properties of Y3(GaAlFe)5O12 liquid-phase epitaxy films with low ferromagnetic resonance losses
Ultra-thin rare earth iron garnet (RIG) films with a narrow ferromagnetic resonance (FMR) line width and a low damping factor have attracted a great deal of attention for microwave and spintronic applications. In this work, 200 nm Y3(GaAlFe)5O12 garnet (GaAl-YIG) films were prepared on gadolinium gallium garnet (GGG) substrates by liquid-phase epitaxy (LPE) with low saturation magnetization. The microstructural properties, chemical composition, and magnetostatic and dynamic magnetization characteristics of the films are discussed in detail. According to the structural analysis, these films exhibit a low surface roughne...
Source: Acta Crystallographica Section B - March 2, 2023 Category: Chemistry Authors: Zhang, Y. Yang, Q. Liu, Y. Hu, A. Zhang, D. Li, H. Yu, J. Huang, J. Lu, Y. Zhang, L. Xue, Q. Li, Y. Jin, L. Wen, Q. Zhang, H. Tags: liquid-phase epitaxy lattice mismatch saturation magnetization FMR line width research papers Source Type: research
Asymmetric rotations and dimerization driven by normal to modulated phase transition in 4-biphenylcarboxy coupled l-phenylalaninate
Amongst the derivatives of 4-biphenylcarboxylic acid and amino acid esters, the crystal structure of 4-biphenylcarboxy-(l)-phenylalaninate is unusual owing to its monoclinic symmetry within a pseudo-orthorhombic crystal system. The distortion is described by a disparate rotational property around the chiral centers ( φ chiral ≃ − 129 ° and 58 ° ) of the two molecules in the asymmetric unit. Each of these molecules comprises planar biphenyl moieties ( φ biphenyl = 0 ° ). Using temperature-dependent single-crystal X-ray diffraction experiments we show that the compound undergoes a phase transition below T ∼ 124 ...
Source: Acta Crystallographica Section B - March 1, 2023 Category: Chemistry Authors: Dey, S. Sasmal, S. Mondal, S. Kumar, S. Chowdhury, R. Sarkar, D. Malla Reddy, C. Peters, L. Roth, G. Haldar, D. Tags: phase transitions intermolecular interactions hydrogen bonding molecular crystals couple rotations modulation steric research papers Source Type: research
Direct interpretation of the X-ray and neutron three-dimensional difference pair distribution functions (3D- Δ PDFs) of yttria-stabilized zirconia
Three-dimensional difference pair distribution functions (3D- Δ PDFs) from X-ray and neutron diffraction experiments are reported for yttria-stabilized zirconia (Zr0.82Y0.18O1.91). A quantitative analysis of the signatures in the three-dimensional difference pair distribution functions is used to establish that oxygen ions neighbouring a vacancy shift by 0.525 (5) Å along 〈 1, 0, 0 〉 towards the vacancy while metal ions neighbouring a vacancy shift by 0.465 (2) Å along 〈 1, 1, 1 〉 away from the vacancy. The neutron 3D- Δ PDF shows a tendency for vacancies to cluster along 〈 ½ ...
Source: Acta Crystallographica Section B - February 24, 2023 Category: Chemistry Authors: Schmidt, E.M. Neder, R.B. Martin, J.D. Minelli, A. Lem é e, M.-H. Goodwin, A.L. Tags: diffuse scattering cubic zirconia three-dimensional difference pair distribution function (3D- Δ PDF) research papers Source Type: research
Analysis of diffuse scattering in electron diffraction data for the crystal structure determination of Pigment Orange 13, C32H24Cl2N8O2
The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the β phase was determined using single-crystal X-ray analysis of a tiny needle. The α phase was investigated using three-dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit-cell parameters with the β phase. The structure solution is described in detail and this provides a...
Source: Acta Crystallographica Section B - February 24, 2023 Category: Chemistry Authors: Gorelik, T.E. Bek ö , S.L. Teteruk, J. Heyse, W. Schmidt, M.U. Tags: 3D electron diffraction electron crystallography diffuse scattering stacking disorder lattice-energy minimization research papers Source Type: research
Incommensurate structures and radiation damage in Rb2V3O8 and K2V3O8 mixed-valence vanadate fresnoites
The structures and phase transitions to incommensurate structures in Rb2V3O8 and K2V3O8 mixed-valence vanadate fresnoites are studied with synchrotron single-crystal diffraction at low temperatures and ambient pressure. Although mixed satellite reflections are absent, the modulated structure of K2V3O8 below 115 K is better described in (3 + 2)- than in (3 + 1)-dimensional space. The geometries of the VO4 and VO5 building units are rigid and it is mainly slight rotations of these polyhedra and small variation of the intermediate K — O distances that are modulated. Prolonged exposure to the high-brillia...
Source: Acta Crystallographica Section B - February 22, 2023 Category: Chemistry Authors: Grzechnik, A. Pet ř í č ek, V. Chernyshov, D. McMonagle, C. Geise, T. Shahed, H. Friese, K. Tags: synchrotron radiation single-crystal diffraction incommensurate structures radiation damage research papers Source Type: research
Efficient modulation of a barium metal – organic framework using amino acids
In recent years, significant advances have been made in the precise control of the physical properties of metal – organic frameworks (MOFs) via the linker-modulated method in which modulators compete with linkers and impose kinetic limitations through crystal growth. In this regard, the structure of a new barium – organic framework [Ba(H2BTC)2(H2O)4]n, BaBTC (BTC = 1,3,5-benzene tricarboxylic acid) is introduced, which allows the competitive coordination strategy and growth orientation of an alkaline-earth metal – organic framework (AEMOF) to be probed without sacrificing phase purity, porosity and crystallinity. The...
Source: Acta Crystallographica Section B - February 20, 2023 Category: Chemistry Authors: Safari, M. Sedghiniya, S. Soleimannejad, J. Janczak, J. Tags: metal – organic framework modulator barium amino acid research papers Source Type: research
Molecular structure of two copper complexes with pharmaceuticals norfloxacin and tinidazole, when powder X-ray diffraction assists multi-domains single-crystal X-ray diffraction. Addendum
(Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - January 20, 2023 Category: Chemistry Authors: Tob ó n Zapata, G.E. Mart í nez Cardona, D.M. Echeverr í a, G.A. Piro, O.E. Tags: norfloxacin copper(II) tinidazole copper(II) X-ray crystal structures vibrational IR spectra thermal decomposition PXRD assisted SCXRD addenda and errata Source Type: research
Solid-state versatility in tranexamic acid drug: structural and thermal behavior of new salts and cocrystals
Tranexamic acid (TNA) is an anti-fibrinolytic hemostatic drug widely used in various medical treatments. Six new salts and five cocrystals of TNA are reported here and the crystal structures of the obtained multicomponent compounds were determined using single-crystal X-ray diffraction (SC-XRD) techniques. TNA formed salts with coformers maleic acid (MEA), nicotinic acid, dl-mandelic acid and saccharin. Salt formation with MEA resulted in three different solid forms, namely TNA – MEA (1:1), TNA – MEA (2:1) and TNA – MEA – H2O (1:1:1). All synthesized TNA salt structures were crystallized as anhydrous ex...
Source: Acta Crystallographica Section B - January 20, 2023 Category: Chemistry Authors: Nechipadappu, S.K. Balasubramanian, S. Tags: cocrystal salt hydrogen bond phase purity powder diffraction research papers Source Type: research
Effect of nano-SiC doping on the structure and superconducting properties of Mg(B1 – xCx)2
Carbon doping is studied in MgB2 pellets during one-step synthesis by solid-state reaction, employing both undoped and carbon-doped boron with and without the addition of nano-SiC. The phase formation during the synthesis as a function of time was followed using powder X-ray diffraction and Rietveld refinement. The superconducting properties were characterized with a magnetometer to investigate doping-induced changes. Mg(B1 – xCx)2 is obtained with nano-precipitates and different compositions depending on the synthesis temperature. It is found that the addition of nano-SiC prevents the phase formation at low temperature ...
Source: Acta Crystallographica Section B - January 18, 2023 Category: Chemistry Authors: Melone, M. Malachevsky, M.T. Sobrero, C.E. Troiani, H. Serquis, A. Tags: superconductor Rietveld microstructure nanostructure kinetics research papers Source Type: research
