Rietveld Refinement of Crystal Structures Using Powder X-ray Diffraction Data: A Comparative Study of Synthesized CuGa1-YInY Te2

1987 ◽  
Vol 42 (12) ◽  
pp. 1493-1499 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Detlev Haase

AbstractThe compounds (Pn4P)4Sb8I28 (1) and (Ph4P)Sb3I10 (2) were prepared by the reaction of SbI3 and Ph4PI in acetonitrile (molar ratios 2:1 and 3:1 respectively). The structures of 1 and 2 were determined from single crystal X-ray diffraction data.1 crystallizes in the triclinic space group P1̄ with a - 1321.7(5). b = 1346.7(5), c = 2201.8(8) pm, α = 104.18(2). β = 99.92(2), γ = 100.33(2)°; 2: monoclinic, C2/c, a = 2371.1(2), b = 745.0(1), c = 2495.1(2) pm, β = 100.75(1)°.Whereas 1 exhibits isolated Sb8I284- ions, the anions of 2 are built up of polymeric chains [Sb3I10- ]∞. In both compounds the distorted Sbl6 octahedra are linked by common edges. The Sb-I distances are in the range between 277.4 and 354.8 pm (1) and between 277.4 and 342.4 pm (2). The observed structures do not only depend on stoichiometry, the nature of the counter cations, and the possibility of oligomerisation but also on the wide variety of the Sb-I bond strengths and the different bridges formed by iodine.The lone pair of Sb(III) seems to be predominantly 5 s2.


2006 ◽  
Vol 62 (4) ◽  
pp. 606-611 ◽  
Author(s):  
Asiloé J. Mora ◽  
Michela Brunelli ◽  
Andrew N. Fitch ◽  
Jonathan Wright ◽  
Maria E. Báez ◽  
...  

The crystal structures of the four-membered heterocycles (S)-(−)-4-oxo-2-azetidinecarboxylic acid (I) and 3-azetidinecarboxylic acid (II) were solved by direct methods using powder synchrotron X-ray diffraction data. The asymmetry of the oxoazetidine and azetidine rings is discussed, along with the hydrogen bonding.


1966 ◽  
Vol 44 (8) ◽  
pp. 939-943 ◽  
Author(s):  
A. K. Das ◽  
I. D. Brown

(NH4)2TeBr6 and Cs2TeBr6 crystals have the cubic K2PtCl6 structure with space group: [Formula: see text] with a0 = 10.728 ± 0.003 Å and 10.918 ± 0.002 Å respectively. The positional coordinate of the bromine atom, and the anisotropic temperature factors of all atoms in the unit cell, have been refined for both crystals by a full matrix least-squares analysis of the three dimensional X-ray diffraction data (R = 0.08). The Te—Br distance, corrected for probable thermal motions of atoms forming the bond, is 2.70 ± 0.01 Å in both crystals.


Author(s):  
Michel Fleck ◽  
Ekkehart Tillmanns ◽  
Ladislav Bohatý ◽  
Peter Held

AbstractThe crystal structures of eight different L-malates have been determined and refined from single-crystal X-ray diffraction data. The compounds are the monoclinic (space groupIn addition, for all the compounds, powder diffraction data were collected, analysed and submitted to the powder diffraction file (PDF).


1996 ◽  
Vol 453 ◽  
Author(s):  
H.-C. Zur Loye ◽  
P. Núñez ◽  
M. A. Rzeznik

AbstractThe one-dimensional compounds Sr3MgPtO6, Sr3MgIrO6, Sr3MgRhO6, Sr3GdRhO6, have been synthesized and structurally characterized by Rietveld refinement of powder X-ray diffraction data. All four compounds are isostructural with the rhombohedral K4CdCl6-type structure. The structure consists of infinite one-dimensional chains of alternating face-shared MO6 octahedra (M = Pt, Ir, Rh) and M′O6 (M′ = Gd, Mg) trigonal prisms. The strontium cations are located in a distorted square antiprismatic environment. Magnetic susceptibility data show that both Sr3MgIrO6 and Sr3MgRhO6 obey the Curie-Weiss law with θ = −6(1) K, and θ= −15(3)K, respectively. Sr3GdRhO6 obeys the Curie law with μeff = 7.80 B.M, consistent with an oxidation state of +3 for both rhodium and gadolinium.


2011 ◽  
Vol 415-417 ◽  
pp. 468-471
Author(s):  
Qiao Hong Yu ◽  
Zheng Fa Li ◽  
Yong Xiang Li ◽  
Ping Zhan Si ◽  
Jiang Ying Wang ◽  
...  

New compounds of sodium samarium titanate Na0.5Sm4.5Ti4O15and sodium europium titanate Na0.5Eu4.5Ti4O15were synthesized successfully by solid state reaction at 1300 oC and 1200 oC, respectively. The lattice parameters of Na0.5Sm4.5Ti4O15and Na0.5Eu4.5Ti4O15were determined at ordinary temperature by using X-ray powder diffraction method. Their Lattice types were determined, and their patterns were indexed. Polycrystalline X-ray diffraction data of sodium samarium titanate were listed. Differences of their crystal structures were analyzed and discussed.


CrystEngComm ◽  
2015 ◽  
Vol 17 (42) ◽  
pp. 8047-8057 ◽  
Author(s):  
Emily R. Draper ◽  
Kyle L. Morris ◽  
Marc A. Little ◽  
Jaclyn Raeburn ◽  
Catherine Colquhoun ◽  
...  

A number of Fmoc amino acids can be effective low molecular weight hydrogelators; we compare single crystal structures to fibre X-ray diffraction data.


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