The specific features of phononic and magnetic subsystems of type-VII clathrate EuNi2P4

2020 ◽  
Vol 22 (32) ◽  
pp. 18025-18034
Author(s):  
V. V. Novikov ◽  
S. L. Bud’ko ◽  
A. V. Matovnikov ◽  
N. V. Mitroshenkov ◽  
K. S. Pilipenko ◽  
...  
Keyword(s):  
Unit Cell ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Two Stage ◽  
Space Group ◽  
Cell Parameters ◽  
Stage Synthesis

EuNi2P4 clathrate with a Eu2+ guest embedded into a Ni–P framework, was synthesized by a two-stage synthesis, confirmed to crystallize in the orthorhombic space group Fddd, unit cell parameters a = 5.1829(1) Å, b = 9.4765(1) Å, and c = 18.9900(1) Å.

Crystal structure and topological affinities of magbasite, KBaFe3+Mg7Si8O22(OH)2F6: a trellis structure related to amphibole and carpholite

2014 ◽  
Vol 78 (1) ◽  
pp. 29-45 ◽  
Author(s):  
M. D. Welch ◽  
R. H. Mitchell ◽  
A. R. Kampf ◽  
A. R. Chakhmouradian ◽  
D. Smith ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Carbonatite Complex ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
Structural Relations ◽  
Final Agreement

AbstractThe crystal structure of magbasite from the Eldor carbonatite complex, Quebec, Canada, has been determined and indicates that the currently accepted formula should be revised to KBaFe3+Mg7Si8O22(OH)2F6. Magbasite is orthorhombic, space group Cmme (Cmma), with unit-cell parameters a 18.9506(3) Å, b 22.5045(3) Å, c 5.2780(1) Å, V 2250.93(6) Å3 (Z = 4). The structure has been solved and refined to final agreement indices R1 = 0.026, wR2 = 0.052, GooF = 1.116 for a total of 2379 unique reflections, and is a new kind of trellis motif related to amphibole and carpholite topologies. An amphibole-like I-beam ‖(100) of edge-sharing octahedrally-coordinated M(1,2,3) sites, which are filled by Mg, is sandwiched between double-chains of SiO4 tetrahedra ‖c. This I-beam is connected to side-ribbons ‖(010) of edge-sharing (Mg,Fe2+)O4(OH,F)2 and Fe3+O4(OH)2 octahedra to form a tunnelled box or trellis structure very like that of carpholite, for which the I-beams are pyroxene-like. K occupies a tunnel site analogous to the A site of amphibole. Ba occupies a cavity site at the corners where the I-beam and side-ribbon meet, and corresponds to the A site of carpholite. The structural relations between magbasite and carpholite are discussed.

The crystal structure of Cu2GeSe3 and the structure-types of the I2-IV-VI3 family of semiconducting compounds

2021 ◽  
Vol 77 (1) ◽  
pp. 158-167
Author(s):  
Analio Dugarte-Dugarte ◽  
Nahum Ramírez Pineda ◽  
Luis Nieves ◽  
José Antonio Henao ◽  
Graciela Díaz de Delgado ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Initial Report ◽  
Space Group ◽  
Cell Parameters ◽  
Semiconducting Compounds ◽  
Bond Valence Model

Almost 50 years after the initial report, the crystal structure of Cu2GeSe3, a I2-IV-VI3 semiconductor, has been revised using modern single-crystal X-ray diffraction data. The structure of this material can be properly described in the monoclinic space group Cc (No. 9) with unit-cell parameters a = 6.7703 (4) Å, b = 11.8624 (5) Å, c = 6.7705 (4) Å, β = 108.512 (6)°, V = 515.62 (5) Å3, Z = 4, rather than in the orthorhombic space group Imm2 (No. 44) with unit-cell parameters a = 11.860 (3), b = 3.960 (1), c = 5.485 (2) Å, V = 257.61 Å3, Z = 2, as originally proposed [Parthé & Garín (1971). Monatsh. Chem. 102, 1197–1208]. Contrary to what was observed in the orthorhombic structure, the distortions of the tetrahedra in the monoclinic structure are consistent with the distortions expected from considerations derived from the bond valence model. A brief revision of the structures reported for the I2-IV-VI3 family of semiconducting compounds (I: Cu, Ag; IV: Si, Ge, Sn; and VI: S, Se, Te) is also presented.

scholarly journals The novel thermostable cellulose-degrading enzyme DtCel5H from Dictyoglomus thermophilum: crystallization and X-ray crystallographic analysis

2018 ◽  
Vol 74 (1) ◽  
pp. 1-5
Author(s):  
Flavia Squeglia ◽  
Rita Berisio ◽  
Alessia Ruggiero
Keyword(s):  
Ammonium Sulfate ◽  
Glycosyl Hydrolase ◽  
Unit Cell ◽  
Structure Stability ◽  
Waste Biomass ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
Dictyoglomus Thermophilum

Cellulose-based products constitute the great majority of municipal waste, and applications of cellulases in the conversion of waste biomass to biofuels will be a key technology in future biorefineries. Currently, multi-enzymatic pre-treatment of biomass is a crucial step in making carbohydrates more accessible for subsequent fermentation. Using bioinformatics analysis, endo-β-(1,4)-glucanase from Dictyoglomus thermophilum (DtCel5H) was identified as a new member of glycosyl hydrolase family 5. The gene encoding DtCel5H was cloned and the recombinant protein was overexpressed for crystallization and biophysical studies. Here, it is shown that this enzyme is active on cellulose substrates and is highly thermostable. Crystals suitable for crystallographic investigations were also obtained in different crystallization conditions. In particular, ordered crystals of DtCel5H were obtained using either ammonium sulfate or polyethylene glycol (PEG) as a precipitant agent. The crystals obtained in the presence of ammonium sulfate belonged to space group P32, with unit-cell parameters a = 73.1, b = 73.1, 73.1, c = 127.8 Å, and diffracted to 1.5 Å resolution, whereas the second crystal form belonged to the orthorhombic space group P212121, with unit-cell parameters a = 49.3, b = 67.9, c = 103.7 Å, and diffracted to 1.6 Å resolution. The crystal structure was solved in both space groups using molecular-replacement methods. Structure–activity and structure–stability studies of DtCel5H will provide insights for the design of high-performance enzymes.

Crystallization of ClfA and ClfB fragments: the fibrinogen-binding surface proteins of Staphylococcus aureus

1999 ◽  
Vol 55 (2) ◽  
pp. 554-556 ◽  
Author(s):  
Champion C. S. Deivanayagam ◽  
Samuel Perkins ◽  
Sita Danthuluri ◽  
Rick T. Owens ◽  
Todd Bice ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Unit Cell ◽  
Surface Proteins ◽  
Asymmetric Unit ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Space Group ◽  
Cell Parameters ◽  
Fibrinogen Binding

Recombinant constructs encoding the fibrinogen-binding domains of ClfA and ClfB from Staphylococcus aureus have been crystallized. ClfA was crystallized in the orthorhombic space group P212121 with unit-cell parameters a = 39.58, b = 81.39 and c = 112.65 Å. A complete data set was recorded to 2.1 Å resolution and had a Vm of 2.3 Å3 Da−1 with 46.5% solvent, suggesting one molecule per asymmetric unit. Co-crystals of ClfA with the 17 amino-acid C-terminal peptide of fibrinogen γ-chain diffracted to 2.1 Å resolution and had unit-cell parameters a = 39.11, b = 81.39 and c = 109.51 Å in the space group P212121. ClfB was crystallized in the tetragonal space group P41212 or P43212 with unit-cell parameters a = 96.31, b = 96.31 and c = 84.13 Å and diffracted to 2.45 Å resolution. The estimated Vm of 2.6 Å3 Da−1 with 53% solvent indicated one molecule in the asymmetric unit.

Synthesis and Spectroscopic Characterization of Mixed Diamidophosphoric Acid Esters: X-Ray Crystal Structure of [(CH3)2N]-[p-H3C-C6H4-O]P(O)X (X = NHC(CH3)3 and p-H3C-C6H4-NH)

2009 ◽  
Vol 64 (5) ◽  
pp. 565-569 ◽  
Author(s):  
Saied Ghadimi ◽  
Mehrdad Pourayoubi ◽  
Ali Asghar Ebrahimi Valmoozi
Keyword(s):  
Spectroscopic Characterization ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
R Value ◽  
Acid Esters

Mixed diamidophosphoric acid esters [(CH3)2N][p-H3C-C6H4-O]P(O)X, where X = NH(CH3) (1), NHCH(CH3)2 (2), NHC(CH3)3 (3) and p-H3C-C6H4-NH (4) were synthesized and characterized by 31P, 31P{1H}, 13C, 1H NMR, and IR spectroscopy and mass spectrometry, and single crystal X-ray diffraction analysis for the compounds 3 and 4. Compound 3 crystallizes in the monoclinic, space group P21/c with unit cell parameters a = 9.006(3), b = 16.286(5), c = 10.319(3) A° , β = 99.633(6)◦, V = 1492.2(8) °A3, Z = 4. The final R value is 0.0622 for 2074 reflections [I ≥ 2σ (I)]. Compound 4 crystallizes in the orthorhombic, space group Pna21 with unit cell parameters a = 7.0459(14), b = 20.934(4), c = 10.436(2) ° A, V = 1539.3(5) °A3, Z = 4. The final R value is 0.0530 for 3025 reflections [I ≥ 2σ (I)].

scholarly journals Synthese und Kristallstruktur von Ba(HSO4)2(H2SO4)3 und Sr(HSO4)2(H2SO4) / Synthesis and Structure of Ba (HSO4)2(H2SO4)3 and Sr(HSO4)2(H2SO4)

1996 ◽  
Vol 51 (7) ◽  
pp. 952-958 ◽  
Author(s):  
C. Werner ◽  
E. Kemnitza ◽  
H. Worzalab ◽  
S. Trojanov
Keyword(s):  
Hydrogen Bonds ◽  
Binary Systems ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
Trigonal Prismatic ◽  
Oxygen Atoms

From the binary systems M2SO4/H2SO4 (M = Ba. Sr), two new hydrogen sulfates, (Ba(HSO4)2(H2SO4)3 and Sr(HSO4)2(H2SO4), have been synthesized and structurally characterized.Ba(HSO4)2(H2SO4)3 crystallizes in the orthorhombic space group P21212, with unit cell parameters a = 4.680(1), b = 11.267(2), c = 29.188(6)A, Z = 4. BaO9 trigonal prismatic polyhedra with Ba-O distances of 2.68 - 3.02 Å from nine different SO4 tetrahedra are connected via common bases and build “isolated” columns consisting of O-S-O bridged double chains along the x-axis. HSO4 and H2SO4 tetrahedra are linked via hydrogen bonds to form columns. Sr(HSO4)2(HTSO4) crystallizes in the triclinic space group P1̄ with unit cell parameters a = 5.971(1), b = 8.468(2), c = 10.226(2)Å, α = 81.71(3), β = 83.30(3), γ = 70.69(3)°, Z = 2. Sr is coordinated by nine oxygen atoms from seven different SO4 tetrahedra with Sr-O distances of 2.47 - 2.84 Å. The SrO9 polyhedra build layers consisting of O-S-O bridged chains. Three crystallographically different SO4 tetrahedra are linked via hydrogen bonds to form a kind of flattened cylinder along the x-axis.

scholarly journals Expression, purification and crystallization of the phosphate-binding PstS protein fromPseudomonas aeruginosa

2014 ◽  
Vol 70 (7) ◽  
pp. 906-910 ◽  
Author(s):  
Avi Neznansky ◽  
Yarden Opatowsky
Keyword(s):  
Crystal Form ◽  
Phosphate Transport ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Solvent Content ◽  
Space Group ◽  
Cell Parameters ◽  
Crystal Volume

Pseudomonas aeruginosa(PA) infections pose a serious threat to human health. PA is a leading cause of fatal lung infections in cystic fibrosis and immune-suppressed patients, of sepsis in burn victims and of nosocomial infections. An important element in PA virulence is its ability to establish biofilms that evade suppression by the host's immune system and antibiotics. PstS, a periplasmic subunit of the Pst phosphate-transport system of PA, plays a critical role in the establishment of biofilms. In some drug-resistant PA strains, PstS is secreted in large quantities from the bacteria, where it participates in the assembly of adhesion fibres that enhance bacterial virulence. In order to understand the dual function of PstS in biofilm formation and phosphate transport, the crystal structure of PA PstS was determined. Here, the overexpression inEscherichia coliand purification of PA PstS in the presence of phosphate are described. Two crystal forms were obtained using the vapour-diffusion method at 20°C and X-ray diffraction data were collected. The first crystal form belonged to the centred orthorhombic space groupC2221, with unit-cell parametersa= 67.5,b= 151.3,c= 108.9 Å. Assuming the presence of a dimer in the asymmetric unit gives a crystal volume per protein weight (VM) of 2.09 Å3 Da−1and a solvent content of 41%. The second crystal form belonged to the primitive orthorhombic space groupP212121, with unit-cell parametersa= 35.4,b= 148.3,c= 216.7 Å. Assuming the presence of a tetramer in the asymmetric unit gives a crystal volume per protein weight (VM) of 2.14 Å3 Da−1and a solvent content of 42.65%. A pseudo-translational symmetry is present in theP212121crystal form which is consistent with a filamentous arrangement of PstS in the crystal lattice.

scholarly journals Novel Fluoridoaluminates from Ammonothermal Synthesis: Two Modifications of K2AlF5 and the Elpasolite Rb2KAlF6

Inorganics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Christian Bäucker ◽  
Peter Becker ◽  
Keshia J. Morell ◽  
Rainer Niewa
Keyword(s):  
Unit Cell ◽  
The Other ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Orthorhombic Unit Cell ◽  
Space Group ◽  
Cell Parameters ◽  
Group Type

Two new modifications of the pentafluoridoaluminate K2AlF5 were obtained from ammonothermal synthesis at 753 K, 224 MPa and 773 K, 220 MPa, respectively. Both crystallize in the orthorhombic space group type Pbcn, with close metric relations and feature kinked chains of cis-vertex-connected AlF6 octahedra resulting in the Niggli formula ∞1{[AlF2/2eF4/1t]2−}. The differences lie in the number of octahedra necessary for repetition within the chains, which for K2AlF5-2 is realized after four and for K2AlF5-3 after eight octahedra. As a result, the orthorhombic unit cell for K2AlF5-3 is doubled in chain prolongation direction [001] as compared to K2AlF5-2 (1971.18(4) pm versus 988.45(3) pm, respectively), while the unit cell parameters within the other two directions are virtually identical. Moreover, the new elpasolite Rb2KAlF6 is reported, crystallizing in the cubic space group Fm3¯m with a = 868.9(1) pm and obtained under ammonothermal conditions at 723 K and 152 MPa.

X-ray powder diffraction data for cobalt tris-ethylenediamine bromide trihydrate and cobalt tris-ethylenediamine iodide hemihydrate

1999 ◽  
Vol 14 (1) ◽  
pp. 49-52
Author(s):  
Hongxiang Wu ◽  
Lidun Ma
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Figures Of Merit

X-ray powder data are given for cobalt tris-ethylenediamine bromide trihydrate, [Co(en)3]Br3·3H2O, and cobalt tris-ethylenediamine iodide hemihydrate, [Co(en)3]I3·0.5H2O. Refined unit-cell parameters for [Co(en)3]Br3·3H2O are a=11.6949(4) Å and c=16.0640(12) Å in trigonal space group P3¯c1(165) or P3c1(158); volume =1902.72 Å3; figures of merit: M20=29, F30=55 (0.0138, 40). Refined unit-cell parameters for [Co(en)3]I3·0.5H2O are a=23.3580(14) Å, b=13.4739(4) Å, and c=11.5421(5) Å in orthorhombic space group Pca21(29) or Pcam(57); volume =3632.57 Å3; figures of merit: M20=37, F30=81 (0.0058, 64).

scholarly journals A new telluride topology: the crystal structure of honeaite Au3TlTe2

2017 ◽  
Vol 81 (3) ◽  
pp. 611-618
Author(s):  
Mark D. Welch ◽  
J. W. Still ◽  
C. M. Rice ◽  
C. J. Stanley
Keyword(s):  
Crystal Structure ◽  
Lone Pair ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
Gold Telluride

AbstractThe crystal structure of the first thallium-bearing gold telluride, honeaite Au3TlTe2, is reported and its topological novelty discussed. Honeaite is orthorhombic, space group Pbcm and unit-cell parameters a = 8.9671(4), b = 8.8758(4), c= 7.8419(5) Å, V = 624.14(6) Å3 (Z = 4). Its structure has been refined to R1 = 0.033, wR2 = 0.053, Goof = 1.087. The structure is based upon a corrugated double-sheet comprising two sub-sheets, each composed of six-memberedrings of corner-linked TeAu3 pyramids in which the Te lone pair is stereoactive. Rows of thallium atoms lie in the grooves between sheets and provide the only inter-sheet connectivity via Tl-Au bonds. There is extensive Au-Au bonding linking the two sub-sheets of the double-sheet.The structure is distinct from those of the 1:2 (Au,Ag)-tellurides: calaverite AuTe2, sylvanite AuAgTe4 and krennerite Au3AgTe8, which are based upon sheet structures with no connecting inter-sheet atoms. It also differs fundamentally from the structuresof synthetic phases Ag3TlTe2 and Ag18Tl4Te11, both of which have an analogous stoichiometry. In contrast to the pyramidal TeAu3 group of honeaite and krennerite, Ag does not form the corresponding TeAg3 group in itstellurides.

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