Structures of four polymorphs of the pesticide dithianon solved from X-ray powder diffraction data

2012 ◽  
Vol 68 (6) ◽  
pp. 661-666 ◽  
Author(s):  
Ivan Halasz ◽  
Robert Dinnebier ◽  
Tiziana Chiodo ◽  
Heidi Saxell
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Weak Interactions ◽  
Rietveld Method ◽  
Carbonyl Groups ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Space Groups

The crystal structures of four polymorphs of the pesticide dithianon (5,10-dihydro-5,10-dioxonaphtho[2,3-b]-1,4-dithiine-2,3-dicarbonitrile) have been solved from powder diffraction data and refined using the Rietveld method. Three polymorphs crystallize in non-centrosymmetric space groups. Two polymorphs have Z′ > 1. The structures are assembled via interactions between carbonyl groups of quinoid fragments into layers which further interact only by weak interactions.

Cristobalite-Related Phases in the NaAlO2–NaAlSiO4 System. I. Two Tetragonal and Two Orthorhombic Structures

1998 ◽  
Vol 54 (5) ◽  
pp. 531-546 ◽  
Author(s):  
J. G. Thompson ◽  
R. L. Withers ◽  
A. Melnitchenko ◽  
S. R. Palethorpe
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Modulation Wave ◽  
Wave Approach ◽  
The Ideal

The crystal structures of five new cristobalite-related sodium aluminosilicates with four different structure types from the system Na2−x Al2−x Si x O4, 0 ≤ x ≤ 1 [Na1.95Al1.95Si0.05O4, P41212, a = 5.2997 (6), c = 7.0758 (9) Å; Na1.75Al1.75Si0.25O4, Pbca, a = 10.4221 (11), b = 14.264 (3), c = 5.2110 (5) Å; Na1.65Al1.65Si0.35O4, P41212, a = 10.3872 (7), c = 7.1589 (8) Å; Na1.55Al1.55Si0.45O4, Pbca, a = 10.385 (1), b = 14.198 (3), c = 5.1925 (6) Å; Na1.15Al1.15Si0.85O4, Pb21 a, a = 10.214 (2), b = 14.226 (7), c = 10.308 (1) Å], have been refined by the Rietveld method from X-ray powder diffraction data. Plausible starting models were derived for the x = 0.05, 0.25 and 0.45 structures by analogy. Starting models for the x = 0.35 and 0.85 structures, with previously unreported structure types, were derived from a modulation wave approach based on distortion of the ideal C9 structure type and assuming regular SiO4 and AlO4 tetrahedra.

The structure of two manganese hexacyanometallates(II): Mn2[Fe(CN)6].8H2O and Mn2[Os(CN)6].8H2O

2002 ◽  
Vol 17 (2) ◽  
pp. 144-148 ◽  
Author(s):  
A. Gómez ◽  
V. H. Lara ◽  
P. Bosch ◽  
E. Reguera
Keyword(s):  
Crystal Structures ◽  
Coordination Sphere ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structural Model ◽  
Rietveld Method ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
Crystallization Water ◽  
X Ray

The crystal structures of two manganese hexacyanometallates(II), Mn2[Fe(CN)6].8H2O and Mn2[Os(CN)6].8H2O, were refined from X-ray powder diffraction data using the Rietveld method, with the reported structure for Mn2[Ru(CN)6].8H2O used as a structural model. These compounds are isomorphous and crystallize in the monoclinic space group P21/n. Their crystallization water is not firmly bound and can be removed without disrupting the M–C≡N–Mn network. In the dehydrated complexes, the outer cation (Mn) remains linked to only three N atoms from CN ligands while the inner cation (Fe,Os) preserves its coordination sphere. The IR, Raman, and Mössbauer spectra for the hydrated and anhydrous forms are explained based on the refined structures.

Crystallographic study of ternary ordered skutterudite IrGe1.5Se1.5

2010 ◽  
Vol 25 (3) ◽  
pp. 247-252 ◽  
Author(s):  
F. Laufek ◽  
J. Návrátil
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Crystallographic Data ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Crystallographic Study ◽  
Related Phase ◽  
The Ideal

The crystal structure of skutterudite-related phase IrGe1.5Se1.5 has been refined by the Rietveld method from laboratory X-ray powder diffraction data. Refined crystallographic data for IrGe1.5Se1.5 are a=12.0890(2) Å, c=14.8796(3) Å, V=1883.23(6) Å3, space group R3 (No. 148), Z=24, and Dc=8.87 g/cm3. Its crystal structure can be derived from the ideal skutterudite structure (CoAs3), where Se and Ge atoms are ordered in layers perpendicular to the [111] direction of the original skutterudite cell. Weak distortions of the anion and cation sublattices were also observed.

The crystal structures of solvent-free alkali-metal squarates from powder diffraction data

2005 ◽  
Vol 220 (11) ◽  
Author(s):  
Robert E. Dinnebier ◽  
Hanne Nuss ◽  
Martin Jansen
Keyword(s):  
High Resolution ◽  
Alkali Metal ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Solvent Free ◽  
Crystallographic Data ◽  
Powder Diffraction Data ◽  
X Ray

AbstractThe crystal structures of solvent-free lithium, sodium, rubidium, and cesium squarates have been determined from high resolution synchrotron and X-ray laboratory powder patterns. Crystallographic data at room temperature of Li

Rietveld Refinement of the BaTiO3 from X-Ray Powder Diffraction

2009 ◽  
Vol 79-82 ◽  
pp. 593-596
Author(s):  
Feng Sun ◽  
Yan Sheng Yin
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Structural Parameters ◽  
Ferroelectric Ceramic ◽  
Powder Diffraction Data ◽  
Ceramic Powders ◽  
Space Group ◽  
X Ray

The ferroelectric ceramic BaTiO3 was synthesized at 1000 °C for 5 h. The structure of the system under study was refined on the basis of X-ray powder diffraction data using the Rietveld method. The system crystallizes in the space group P4mm（99）. The refinement of instrumental and structural parameters led to reliable values for the Rp, Rwp and Rexp.We use the TOPAS software of Bruker AXS to refine this ceramic powders and show its conformation

The BaAl4 Structure and its Derivatives from the R-Zn-Ga Systems

2012 ◽  
Vol 194 ◽  
pp. 5-9 ◽  
Author(s):  
Yuriy Verbovytskyy ◽  
Antonio Pereira Gonçalves
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
First Time

Seven new ternary RZn1+xGa3-x (R = Ce, Pr, Nd, Sm, Ho and Er) and R5Zn2Ga17 (R = Ce) phases are synthesized for the first time. Their crystal structures are solved on basis of X-ray powder diffraction data. The above mentioned compounds belong to the BaAl4 (space group I4/mmm) and Rb5Hg19 (space group I4/m) structure types. Details of the structure of the Ce5Zn2Ga17 compound and relationship with RZn2-xGa2+x (BaAl4 type) and R3Zn8-xGa3+x (La3Al11 type) are briefly discussed.

Structure Refinements of the Layered Intergrowth Phases SbIIISbV x A 1−x TiO6 (x≃0, A = Ta, Nb) Using Synchrotron X-ray Powder Diffraction Data

1997 ◽  
Vol 53 (6) ◽  
pp. 861-869 ◽  
Author(s):  
C. D. Ling ◽  
J. G. Thompson ◽  
S. Schmid ◽  
D. J. Cookson ◽  
R. L. Withers
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Homologous Series ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
The Family

The structures of the layered intergrowth phases SbIIISb^{\rm V}_xAl-xTiO6 (x \simeq 0, A = Ta, Nb) have been refined by the Rietveld method, using X-ray diffraction data obtained using a synchrotron source. The starting models for these structures were derived from those of Sb^{\rm III}_3Sb^{\rm V}_xA 3−xTiO14 (x = 1.26, A = Ta and x = 0.89, A = Nb), previously solved by single-crystal X-ray diffraction. There were no significant differences between the derived models and the final structures, validating the approach used to obtain the models and confirming that the n = 1 and n = 3 members of the family, Sb^{\rm III}_nSb^{\rm V}_xA n−xTiO4n+2 are part of a structurally homologous series.

scholarly journals Quantitative Phase Analysis of Skarn Rocks by the Rietveld Method Using X-ray Powder Diffraction Data

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 894
Author(s):  
Yana Tzvetanova ◽  
Ognyan Petrov ◽  
Thomas Kerestedjian ◽  
Mihail Tarassov
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
Quantitative Phase Analysis ◽  
Chemical Compositions ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Fine Grained ◽  
Variable Chemical

The Rietveld method using X-ray powder diffraction data was applied to selected skarn samples for quantitative determination of the present minerals. The specimens include garnet, clinopyroxene–garnet, plagioclase–clinopyroxene–wollastonite–garnet, plagioclase–clinopyroxene–wollastonite, plagioclase–clinopyroxene–wollastonite–epidote, and plagioclase–clinopyroxene skarns. The rocks are coarse- to fine-grained and characterized by an uneven distribution of the constituent minerals. The traditional methods for quantitative analysis (point-counting and norm calculations) are not applicable for such inhomogeneous samples containing minerals with highly variable chemical compositions. Up to eight individual mineral phases have been measured in each sample. To obtain the mineral quantities in the skarn rocks preliminary optical microscopy and chemical investigation by electron probe microanalysis (EPMA) were performed for the identification of some starting components for the Rietveld analysis and to make comparison with the Rietveld X-ray powder diffraction results. All of the refinements are acceptable, as can be judged by the standard indices of agreement and by the visual fits of the observed and calculated diffraction profiles. A good correlation between the refined mineral compositions and the data of the EPMA measurements was achieved.

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