X-ray powder diffraction characterization of disilver trihydrogen paraperiodate

2006 ◽  
Vol 21 (1) ◽  
pp. 52-55
Author(s):  
Norberto Masciocchi ◽  
Davide Gianni

X-ray powder diffraction data for the trigonal form of disilver trihydrogen paraperiodate, Ag2H3IO6, are reported. The cell parameters are a=5.941 89(3), c=12.7253(1) Å, V=389.089(6) Å3, and ρ=5.65 g cm−3 for Z=3. A full-profile Rietveld refinement confirms the monophasic nature of the sample and the presence of two-dimensional corrugated layers of the A2BO6 type linked by hydrogen bonds. Short unsupported Ag–Ag contacts (about 3.02 Å) of the argentophilic type are also shown.

2002 ◽  
Vol 17 (1) ◽  
pp. 1-6 ◽  
Author(s):  
D. Louër ◽  
V. Moise ◽  
M. Liégeois-Duyckaerts ◽  
A. Rulmont

Three phosphates, MIBaIn2(PO4)3 with MI=Na, K, Cs, isostructural to the langbeinite structure, have been studied from powder diffraction data collected with monochromatic radiation obtained from a conventional X-ray source. Precise powder data are reported, as well as cell parameters, i.e., a=10.026 08(9) Å, a=10.121 57(13) Å and a=10.226 94(9) Å for MI=Na, K and Cs, respectively. A Rietveld refinement has been carried out (space group P213), with final RF factors, 0.061, 0.041 and 0.027, and Rwp factors, 0.196, 0.142 and 0.129, for MI=Na, K and Cs, respectively. There are two octahedrally coordinated In3+ ions in the asymmetric unit and the final refinements suggest disorder on the two sites of the MI/Ba sublattice.


2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 355 ◽  
Author(s):  
G. E. Delgado ◽  
And V. Sagredo

The crystal structure of the quaternary compound Cu2NiGeS4, belonging to the system I2-II-IV-VI4, was characterized by Rietveld refinement using X-ray powder diffraction data. This material crystallize with a stannite structure in the tetragonal space group I2m (Nº 121), Z = 2, unit cell parameters a = 5.3384(1) Å, c = 10.5732(3) Å, V = 301.32(3) Å3, acknowledged as a normal valence adamantane-structure.


1994 ◽  
Vol 58 (393) ◽  
pp. 615-620 ◽  
Author(s):  
Gilberto Artioli ◽  
Harry Foy

AbstractThe rare zeolite mineral gobbinsite has been found in vugs of altered basalts at the Magheramorne Quarry, Lane, Northern Ireland, intimately associated with phillipsite. The crystal chemistry of the sample (Na4.3Ca0.6Si10.4Al5.6O32·12H2O) is close to that reported for gobbinsite from the type locality. The crystal structure of the Magheramorne gobbinsite has been refined from X-ray powder diffraction data using the multiphase Rietveld full profile technique. The orthorhombic Pmn21 space group is confirmed. The refined cell parameters (a = 10.1027(5), b = 9.8016(5), and c = 10.1682(6) Å) are slightly different from those reported in the literature for the K-rich gobbinsite from Island Magee (a = 10.108(1), b = 9.766(1), and c = 10.171(1) Å), whose structure was also refined from powder data.


2019 ◽  
Vol 70 (7) ◽  
pp. 2379-2384
Author(s):  
Gheorghe Branoiu ◽  
Ibrahim Ramadan

The crystal structure of a spectacular sample of stilbite from Pune region located in the Deccan Traps (western India) has been refined using X-Ray powder diffraction data and the Rietveld method. The Rietveld refinement was carried out using the computer program Diffracplus TOPAS 4.1. The pseudo-Voigt (pV) profile function was used for the fit of the peaks. The Rietveld refinement of the analyzed sample in the space group C2/m (No.12): a=13.606 �, b=18.260 �, c=11.253 �, b=127.432�, Z=8, confirm the basic stilbite structure. The chemical composition of the stilbite crystals from Pune region (India) was determined by EDX analysis. The paper presents a new set of the unit cell parameters and fractional coordinates that define the stilbite crystal structure. The quality of the sample analyzed was pristine, the sample being collected from an association of apophyllite-stilbite crystals of centimetric dimensions.


2001 ◽  
Vol 16 (1) ◽  
pp. 46-47
Author(s):  
Petr Melnikov ◽  
Alexandre Cuin ◽  
Pedro P. Corbi ◽  
Maurício Cavicchioli ◽  
Antonio C. Massabni

X-ray powder diffraction data for the orthorhombic natural amino acid djenkolic acid, C7H14N2O4S2, is described in this paper. The orthorhombic cell parameters are: a=8.12 Å, b=12.16 Å, and c=5.38 Å


2007 ◽  
Vol 22 (4) ◽  
pp. 292-294 ◽  
Author(s):  
Y. P. Sun ◽  
Yinxiao Du ◽  
W. Y. Wang ◽  
Ming He ◽  
G. M. Cai ◽  
...  

Crystal structure of a new compound KBaB5O9 has been investigated from X-ray powder diffraction data. This compound is isostructural with KSrB5O9 and crystallizes in the monoclinic system with space group P21/c. Unit-cell parameters are a=6.7200(2) Å, b=8.3256(2) Å, c=14.3674(4) Å, and β=92.6103(3) deg. Its structure contains both B3O7 and B3O8 rings, which share a common B atom to form a complex two dimensional network constituting the basic B5O9 unit in the formula. Adjacent networks are bound together by Ba and K atoms, which have eight- and nine-coordinate sites, respectively. In addition, DTA and TGA curves reveal that KBaB5O9 decomposes at 798 °C. Photoluminescence (PL) characteristics of KBaB5O9:Eu3+ have been studied. The PL spectra show the strongest emission at 618 nm and the quench concentration of Eu3+ is 4 at. %.


1999 ◽  
Vol 55 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Maryjane Tremayne ◽  
Elizabeth J. MacLean ◽  
Chiu C. Tang ◽  
Christopher Glidewell

The crystal structure of 2,4,6-triisopropylbenzenesulfonamide, C15H25NO2S, has been solved from X-ray powder diffraction data collected at 120 (1) K using synchrotron radiation and refined by Rietveld methods. The structure was solved by the application of a Monte Carlo method in which trial structures were generated by random movement of the molecule in the unit cell and assessed using a full-profile-fitting technique. Intramolecular flexibility was introduced into the structure solution in the form of four independent asymmetric rotors, allowing the isopropyl and sulfonamide groups to rotate freely within the molecule. The structure is monoclinic P21/c, a = 16.9600 (6), b = 8.1382 (2), c = 11.7810 (2) Å, β = 104.777 (2)° with Z = 4. The molecules are linked by N—H...O hydrogen bonds, with N...O distances of 2.77 (1) and 2.92 (1) Å, into two-dimensional sheets built from R^2_2(8) and R^6_6(20) rings.


2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.


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