Crystal structure of calcium cobalt orthophosphate, CaCo[Ca0.1Co0.9](PO4)2

2006 ◽  
Vol 21 (3) ◽  
pp. 220-224
Author(s):  
Koichiro Fukuda ◽  
Hajime Hasegawa ◽  
Tomoyuki Iwata ◽  
Shinobu Hashimoto

Crystal structure of Ca1.1Co1.9(PO4)2 was successfully determined from laboratory X-ray powder diffraction data (Co Kα) using direct methods and the Rietveld refinement. The crystal structure was found to be monoclinic (space group P21∕n, Z=4) with lattice dimensions of a=1.452 67(5) nm, b=0.494 34(1) nm, c=0.867 50(3) nm, β=92.316(1)°, and V=0.622 45(3) nm3. The final reliability indices calculated from the Rietveld refinement were Rwp=3.93%, Rp=3.02%, RB=4.10%, and S=1.48. Both Co and Ca atoms were distributed over the 2a and 2d sites with a preference of Ca at the 2d site. The coexistence of Co and Ca on the 2a and 2d sites is indispensable for stabilizing Ca1.1Co1.9(PO4)2 in the Ca3(PO4)2-Co3(PO4)2 system.

2003 ◽  
Vol 18 (2) ◽  
pp. 140-143 ◽  
Author(s):  
Lingmin Zeng ◽  
Liangwei Chen ◽  
Shaoping Pu ◽  
Yikun Yang ◽  
Wenggui Gao ◽  
...  

X-ray powder diffraction data for the anticancer drug PtCl2(C2H3O2)2(C6H13N)(NH3) are reported. The crystal structure of PtCl2(C2H3O2)2(C6H13N)(NH3) obtained from a Rietveld refinement are: space group P21/a, a=13.547(2) Å, b=8.260(1) Å, c=14.638(3) Å, β=110.429(2)°, V=1534.96 Å3, Z=4 and Dcalc.=2.068 Mg/m3.


1999 ◽  
Vol 14 (4) ◽  
pp. 284-288 ◽  
Author(s):  
Hoong-Kun Fun ◽  
Ping Yang ◽  
Minoru Sasaki ◽  
Masasi Inoue ◽  
Hideoki Kadomatsu

The crystal structure of γ-Mo4O11 was obtained at room temperature (296 K) by Rietveld analysis with X-ray powder diffraction data. The crystal belongs to orthorhombic system, space group: Pna21, Z=4, Mr=559.753 (Atomic weights 1977), Dx=4.1228 g/cm3, F(000)=1024.0, μ=451.293 cm−1 (Int. Tab. Vol. C, Table 4.2.4.2, p. 193, λ=1.540 60 Å), a=24.4756(5) Å, b=6.7516(1) Å, c=5.4572(1) Å, and V=901.80(3) Å3. The structure was refined to Rwp=5.60%, Rp=4.27%, Rb=3.36%, and Rf=2.74% for 65 parameters with 3541 step intensities and 3055 peaks. Goodness of the fit S=3.35.


1993 ◽  
Vol 8 (1) ◽  
pp. 54-56 ◽  
Author(s):  
Peter C. Burns ◽  
Frank C. Hawthorne

The crystal structure of α-CoSO4 has been refined by the Rietveld method from X-ray powder diffraction data. The structure is orthorhombic, space group Pnma, a = 8.6127(4), b = 6.7058(3), c = 4.7399(2) Å, V = 273.75(3) Å3. Final RB = 2.41%, RP = 5.24%, RWP=6.66%, RWP (expected) =5.74% (WP =weighted profile). The structure consists of edge-sharing octahedral chains parallel to [010] interconnected by SO4 tetrahedra.


2015 ◽  
Vol 1089 ◽  
pp. 102-106
Author(s):  
Liu Qing Liang ◽  
Wen Jun Shen ◽  
Ling Min Zeng ◽  
Cai Min Huang

A new ternary compound TbCo0.67Ga1.33 was discovered and studied by means of X-ray powder diffraction technique. The crystal structure of the new compound was refined by using Rietveld method from X-ray powder diffraction data. This compound crystallizes in the orthorhombic with the CeCu2 structure type( space group Imma, a = 0.43384(6) nm, b = 0.70193(1) nm, c = 0.75617(1) nm, Z = 4, and Dcalc = 8.512 g/cm3 ). The Rietveld refinement results were Rp = 0.0996, Rwp = 0.1277.


2009 ◽  
Vol 79-82 ◽  
pp. 593-596
Author(s):  
Feng Sun ◽  
Yan Sheng Yin

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


2014 ◽  
Vol 78 (2) ◽  
pp. 347-360 ◽  
Author(s):  
F. Colombo ◽  
J. Rius ◽  
O. Vallcorba ◽  
E. V. Pannunzio Miner

AbstractThe crystal structure of sarmientite, Fe23+ (AsO4)(SO4)(OH)·5H2O, from the type locality (Santa Elena mine, San Juan Province, Argentina), was solved and refined from in-house powder diffraction data (CuKα1,2 radiation). It is monoclinic, space group P21/n, with unit-cell dimensions a = 6.5298(1), b = 18.5228(4), c = 9.6344(3) Å, β = 97.444(2)º, V = 1155.5(5) Å3, and Z = 4. The structure model was derived from cluster-based Patterson-function direct methods and refined by means of the Rietveld method to Rwp = 0.0733 (X2 = 2.20). The structure consists of pairs of octahedral-tetrahedral (Fe−As) chains at (y,z) = (0,0) and (½,½), running along a. There are two symmetry-independent octahedral Fe sites. The Fe1 octahedra share two corners with the neighbouring arsenate groups. Both individual chains are related by a symmetry centre and joined by two symmetry-related Fe2 octahedra. Each Fe2 octahedron shares three corners with double-chain polyhedra (O3, O4 with arsenate groups; the O8 hydroxyl group with the Fe1 octahedron) and one corner (O11) with the monodentate sulfate group. The coordination of the Fe2 octahedron is completed by two H2O molecules (O9 and O10). There is also a complex network of H bonds that connects polyhedra within and among chains. Raman and infrared spectra show that (SO4)2− tetrahedra are strongly distorted.


2000 ◽  
Vol 15 (3) ◽  
pp. 191-192 ◽  
Author(s):  
Luz Amparo Palacio ◽  
Carlos Saldarriaga

Powder diffraction data were collected for a synthetic zinc molybdate of composition Na(OH)Zn2(MoO4)2·2.5H2O. The material is monoclinic, space group C2/m, with a=9.4543(12), b=6.3492(7), c=7.6453(11), β=115.899(13), and V=412.83 Å3.


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).


1995 ◽  
Vol 10 (2) ◽  
pp. 86-90 ◽  
Author(s):  
R. Černý ◽  
K. Yvon ◽  
T. I. Yanson ◽  
M. B. Manyako ◽  
O. I. Bodak

Y6Cr4+xAl43−x (x = 2.57); space group P63/mcm, a = 10.8601(1) Å, c = 17.6783(3) Å, V= 1805.7(1) Å3, Z=2; isostructural to Yb6Cr4+xAl43−x, (x=1.76) with two aluminium sites partially occupied by chromium (44% and 27% Cr). YCr4−xAl8+x (x=1.22); space group I4/mmm, a = 9.0299(2) Å, c = 5.1208(2) Å, V=417.55(3) Å3, Z=2, disordered variant of CeMn4Al8 with one chromium site (8f) partially occupied by aluminium (33% Al); X-ray powder diffraction data were collected on a well-crystallized multiphase sample containing 43 wt.% of Y6Cr4+xAl43−x, 27 wt.% of Y2Cr8−xAl16+x, 16 wt.% of Al, 13 wt.% of YAl3, and traces of Y2O3. Structure refinement converged at Rwp = 2.0% and RB = 3.5, 3.6% resp. for a total of 78 parameters and 1190 reflections.


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