Atomanordnung und Strukturverfeinerung von Cancrinit

1965 ◽  
Vol 122 (1-6) ◽  
pp. 407-422
Author(s):  
O. Jarchow
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Three Dimensional ◽  
The Other ◽  
Threefold Axis ◽  
Space Group ◽  
X Ray

Abstract X-ray photographe of (Ca, Na)CO3 cancrinites show diffuse satellites with the indices (h k l ± 3/7), The examined crystals from Litchfield, U.S.A., have the space group P63 and the lattice dimensions a = 12.75 Å and c = 5.14 Å. The crystal structure has been determined-independently of all previous structure assumptions-from the relation of the transformation hauyn-canorinite and refined on three-dimensional data by the least-squares method to R = 0.089. The structure is composed of an ordered Si, Al framework with channels around the threefold axis and the axis 63; the other cations and anions as Na, Ca, H2O, CO3 etc. are enclosed in these channels.

Verfeinerung der Kristallstruktur eines basaltischen Magnesio-Hastingsites

1981 ◽  
Vol 156 (3-4) ◽  
Author(s):  
E. M. Walitzi ◽  
F. Walter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the basaltic clino-amphibole magnesio-hastingsite was refined from three-dimensional photographic X-ray data by a full matrix least-squares method in the space group

The crystal structure of kogarkoite, Na3SO4F

1980 ◽  
Vol 43 (330) ◽  
pp. 753-759 ◽  
Author(s):  
L. Fanfani ◽  
G. Giuseppetti ◽  
C. Tadini ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Thermal Parameters ◽  
Cell Content ◽  
Space Group ◽  
X Ray ◽  
Structural Relationships ◽  
Automatic Diffractometer ◽  
Monoclinic Cell

SummaryThe crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

THE CRYSTAL STRUCTURE OF K2TeBr6

1964 ◽  
Vol 42 (12) ◽  
pp. 2758-2767 ◽  
Author(s):  
I. D. Brown
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Least Squares ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cubic Form ◽  
Efficient Packing

Crystals of K2TeBr6 are monoclinic, space group [Formula: see text] with a = 7.521, b = 7.574, and c = 10.730 Å; β = 89° 40′. Atomic positions have been found by three dimensional X-ray diffraction analysis (least squares R = 0.12). The crystals possess a K2PtCl6 structure which is distorted to allow a more efficient packing of the comparatively large anions than is possible with the undistorted cubic form. The stereochemistry of the octahedral TeBr6− ion (Te—Br = 2.71 Å) is discussed.

The crystal and molecular structure of aqua-bis(ethylenediamine)cupric-tris(cyano)-selenocyanatodicuprate

1982 ◽  
Vol 47 (10) ◽  
pp. 2623-2632 ◽  
Author(s):  
Viktor Vrábel ◽  
Jan Lokaj ◽  
Ján Garaj ◽  
František Pavelčík
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structural Analysis ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Triclinic System

The crystal structure of [Cu(H2O)(en)2][Cu2(CN)3(SeCN)] was solved by single crystal X-ray structural analysis in the triclinic system with a space group of P1 and in the monoclinic system with a space group of C2. In the triclinic system the unit cell has dimensions of a = 0.8445(3), b = 0.7903(3), c = 0.8444(3) nm, α = 119.58(2), β = 118.59(2) and γ = 93.63(3)° and, in the monoclinic system, a = 1.3331(4), b = 0.8670(2), c = 0.8267(3), β = 122.60(2)°. The structure was refined by the least squares method to final value of R = 5.5% in the triclinic system and R = 7.8% in the monoclinic system. The coordination sphere around the Cu(II) atom is square pyramidal, formed of two ethylenediamine molecules and one water molecule. The Cu(I) atoms are tetrahedrally coordinated by bridging SeCN and CN ligands to form infinite three-dimensional chains. The SeCN group is bonded to the Cu(I) atoms through the Se atom at distances of 0.2731(3) and 0.2745(3) nm.

Coordination compounds of Hg22+: The crystal structure of Bis(acridine)dimercury(I) perchlorate

1976 ◽  
Vol 29 (4) ◽  
pp. 723 ◽  
Author(s):  
D Taylor
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Coordination Compounds ◽  
Three Dimensional ◽  
Mercury Atom ◽  
Steric Interaction ◽  
Space Group ◽  
X Ray ◽  
Metal Ligand ◽  
Block Diagonal

Crystals of bis(acridine)dimercury(1) perchlorate, [Hg2(C13H9N)2] (ClO4)2 are monoclinic, a = 10.629(1), b = 16.841(2), c = 7.142(1) �, β = 99.06(2)�, space group I2/m with Z = 2 dimeric formula units. The structure was solved from three-dimensional diffractometer X-ray data(1427 independent reflections), block-diagonal least-squares refinement of all atoms, including hydrogens, converging at R = 0.028. The mercury dimer, Hg-Hg 295177(5)�, is coordinated in the axial positions by the acridine molecules, Hg-N 2.150(5) �, the cation having C2h symmetry.There are also two long contacts from each mercury atom to oxygen atoms of the perchlorate ions, Hg-0 2.958(6) �. Evidence for a metal-ligand steric interaction is presented.

Crystal structure of biphenylenyliodonium[bis(phenylsulphonyl)] methylsulphonylmethylide, C28H21IO6S3

1994 ◽  
Vol 209 (6) ◽  
Author(s):  
A. P. Bozopoulos ◽  
C. A. Kavounis ◽  
G. A. Stergioudis ◽  
P. J. Rentzeperis ◽  
A. Varvoglis
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Computer Controlled

AbstractThe crystal and molecular structure of the title compound (BPIS hereafter) has been determined from three-dimensional X-ray data, measured on a computer-controlled STOE AED 2 diffractometer. The structure is triclinic Space groupThe structure was solved by Patterson and Fourier syntheses and refined by least-squares calculations to a finalTwo I-C

Crystal structure of the ferromagnetic polymer potassium Bis(carbonato)cuprate(II)

1980 ◽  
Vol 33 (2) ◽  
pp. 431 ◽  
Author(s):  
A Farrand ◽  
AK Gregson ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Square Planar

The crystal structure of the title compound, K2Cu(CO3)2, has been determined by single-crystal X-ray diffraction at 295(1) K, and refined by least squares to a residual of 0.027 for 1441 'observed' reflections. Crystals are orthorhombic, space group Fdd2, a 11.425(3), b 17.658(4), c 6.154(2) A, Z 8. The structure comprises potassium cations embedded in an infinite three-dimensional polymeric anionic array of square-planar coordinated copper atoms with bridging carbonate groups [Cu-O 1.934(2), 1.936(2) Ǻ]. Within the latter, the non- coordinating oxygen-carbon bond is shorter [1.259(3) Ǻ] than the other two [1.303(3), 1.307(2) Ǻ] and the O-C-O angle opposite it is correspondingly reduced to 117.1(2)°. The CO3 plane lies at 83.9° to the CuO4 'plane'.

Die Röntgenstrukturanalyse von (CO)9Co3CΟΒΒr2Ν(C5)3. X-ray Structure Analysis of (CO)9Co3COBBr2N(C2H5)3

1976 ◽  
Vol 31 (3) ◽  
pp. 342-344 ◽  
Author(s):  
Volker Bätzel
Keyword(s):  
Least Squares ◽  
Structure Analysis ◽  
Reliability Index ◽  
Three Dimensional ◽  
Diagonal Matrix ◽  
Crystal Data ◽  
Block Diagonal Matrix ◽  
Fourier Methods ◽  
Space Group ◽  
X Ray

Using three dimensional X-ray data collected on a four circle diffractometer, the structure of (CO)9Co3COBBr2N(C2H5)3 was solved by Patterson and Fourier methods. Least squares refinement with a block-diagonal matrix leads to a reliability index of R = 10.7%. Crystal data: α = 13.277(6) Å, b = 10.17(1) Å, c = 9.22(2) Å; α = 91.12(6)°, β = 87.61(4)°, γ = 98.79(2)°; space group P1̅; Z = 2; V = 1229,7 Å3; Dx = 1.97 gcm-3.

The crystal structure of gersdorffite (III), a distorted and disordered pyrite structure

1968 ◽  
Vol 36 (283) ◽  
pp. 940-947 ◽  
Author(s):  
P. Bayliss ◽  
N. C. Stephenson
Keyword(s):  
Crystal Structure ◽  
Metal Atom ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Partially Ordered ◽  
The Ideal

SummaryThe crystal structure of gersdorffite (III) has been examined with three-dimensional Weissenberg X-ray diffraction data. The unit cell is isometric with a 5·6849 ± 0·0003 Å, space group PI, and four formula units per cell. This structure has the sulphur and arsenic atoms equally distributed over the non-metal atom sites of pyrite. All atoms show significant random displacements from the ideal pyrite positions to produce triclinic symmetry, which serves to distinguish this mineral from a disordered cubic gersdorffite (II) and a partially ordered cubic gersdorffite (I). Factors responsible for the atomic distortions are discussed.

Über das Erdalkalimetall-Lanthanoid-Kupfer-Oxomolybdat (Cu0,22Mg0 ,78)BaNd2Mo4O16/The Alkaline Earth Rare Earth Copper-Oxomolybdate (Cu0.22Mg0.78)BaNd2Mo4O16

1995 ◽  
Vol 50 (4) ◽  
pp. 577-580 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

Single crystals of (Cu0.22Mg0.78)BaNd2Mo4O16 have been prepared by crystallization from melts and investigated by X-ray methods. The compound crystallizes monoclinically, space group C62h - C12/c1, Z = 4, a = 5.351(1), b = 12.891(2), c = 19.391(4) Å,β = 90.899(14)° and is isotypic to CuKHo2Mo4O16. The crystal structure is dominated by BaO10 and NdO8 polyhedra forming a three-dimensional polyhedra network, which is filled by axially distorted (Cu,Mg)O6 octahedra and MoO4 tetrahedra.

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