Crystal structure of cyanometallates Me3[Co(CN)6]2 and KMe[Fe(CN)6] with Me=Mn2+, Ni2+, Cu2+

1999 ◽  
Vol 14 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Grzegorz Małecki ◽  
Alicja Ratuszna
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Powder Diffraction Data ◽  
Bridging Ligands ◽  
Cubic Symmetry ◽  
X Ray ◽  
C And N ◽  
Starting Model

The crystal structure of four cyanometallates has been determined from X-ray powder diffraction data using the Rietveld method. The variously hydrated compounds Cu3[Co(CN)6]2, Mn3[Co(CN)6]2 and KNi[Fe(CN)6] crystallize at cubic symmetry (Fm3m) with lattice parameters 10.032(2), 10.413(3) and 10.234(5) Å, respectively. The crystal of KMn[Fe(CN)6]·2H2O shows a monoclinic structure (P21/c) with the lattice parameters a=10.108(2) Å, b=10.104(3) Å, c=10.114(3) Å, β=92°, 93°. The starting model was based on an isomorphic Mn3[Co(CN)6]2 single crystal structure, where Co and Mn ions are octahedrally coordinated by C and N atoms, respectively, forming three-dimensional bimetallic networks with the C≡N groups as bridging ligands.

Crystal structure of the three-dimensional magnetic network of type Mek[Fe(CN)6]l·mH2O, where Me=Cu, Ni, Co

1995 ◽  
Vol 10 (4) ◽  
pp. 300-305 ◽  
Author(s):  
A. Ratuszna ◽  
S. Juszczyka ◽  
G. Małecki
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Bridging Ligands ◽  
X Ray ◽  
C And N ◽  
Fe Sites ◽  
Magnetic Network

The crystal structures of Mek[Fe(CN)6];l·mH2O where Me = Cu, Ni and Co, have been refined from X-ray (CuKa) powder diffraction data by means of Rietveld analyses in space group . The Fe and Me ions are octahedrally coordinated by C and N atoms respectively, forming three-dimensional bimetallic networks with the CN-groups as bridging ligands. The Me(l) sites (k = 2, l=1) and the Fe sites (k = 3, l = 2) are partially occupied. Water oxygens were placed in alternative, empty metal sites.

Crystal structure of calcium zirconium diorthophosphate, CaZr(PO4)2

2003 ◽  
Vol 18 (4) ◽  
pp. 296-300 ◽  
Author(s):  
Koichiro Fukuda ◽  
Kazuko Fukutani
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Direct Methods ◽  
Dimensional Structure ◽  
Pentagonal Bipyramid ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Reliability Indices

The crystal structure of CaZr(PO4)2 was determined from conventional X-ray powder diffraction data using direct methods, and it was further refined by the Rietveld method. The structure was orthorhombic (space group P212121, Z=4) with a=1.448 76(4), b=0.672 13(1), c=0.623 47(2) nm, and V=0.607 10(3) nm3. Final reliability indices were Rwp=6.49%, RB=2.43%, and S=1.32. The Ca atom is sevenfold coordinated, and the Ca atom and surrounding oxygen atoms form a distorted capped octahedron with a mean Ca–O distance of 0.243 nm. The ZrO7 coordination polyhedron is a distorted pentagonal bipyramid with a mean Zr–O distance of 0.216 nm. CaO7, ZrO7, and PO4 polyhedra share edges to form infinite chains with the composition [CaO3ZrO3P2O8]12− along the [010]. Individual chains are linked together, forming a two-dimensional sheet parallel to (100). These sheets are stacked in the [100] direction to form a three-dimensional structure.

Synthesis and Rietveld refinement of skutterudite-related phase CoSn1.5Te1.5

2008 ◽  
Vol 23 (1) ◽  
pp. 15-19 ◽  
Author(s):  
F. Laufek ◽  
J. Návrátil ◽  
V. Goliáš
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Title Compound ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Cubic Symmetry ◽  
X Ray ◽  
Long Range Ordering ◽  
Related Phase

Crystal structure of the skutterudite-related phase has been refined by the Rietveld method from X-ray powder diffraction data. Refined crystallographic data for CoSn1.5Te1.5 are a=12.9063(2) Å, c=15.7837(3) Å, V=2276.89(4) Å3, space group R3 (No. 148), Z=24, and Dx=7.50 g/cm3. The crystal structure of the title compound can be viewed as a modification of the skutterudite structure (CoAs3)—it is isostructural with CoGe1.5Te1.5 and IrSn1.5Te1.5. In the structure of CoSn1.5Te1.5, the Sn and Te atoms exhibit long-range ordering, which results in lowering of the original cubic symmetry of the skutterudite structure to the trigonal one.

X-ray powder diffraction study of LiCrP2O7

2007 ◽  
Vol 63 (3) ◽  
pp. i70-i72 ◽  
Author(s):  
Ludmila S. Ivashkevich ◽  
Kirill A. Selevich ◽  
Anatoly I. Lesnikovich ◽  
Anatoly F. Selevich
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
Dimensional Network ◽  
Tetrahedral Environment

The monoclinic crystal structure of lithium chromium(III) diphosphate, LiCrP2O7, isotypic with other members of the series LiM IIIP2O7 (M III = Mn, Fe, V, Mo, Sc and In), was refined from laboratory X-ray powder diffraction data using the Rietveld method. The Cr3+ cation is bonded to six O atoms from five diphosphate anions to form a distorted octahedron. Links between the bent diphosphate anions and the Cr3+ cations result in a three-dimensional network, with tunnels filled by the Li+ cations in a considerably distorted tetrahedral environment of O atoms.

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

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.

Crystal structure of (Z)-cefprozil monohydrate, C18H19N3O5S(H2O)

2019 ◽  
Vol 34 (4) ◽  
pp. 379-388
Author(s):  
Zachary R. Butler ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Density Functional ◽  
Three Dimensional ◽  
Ion Pair ◽  
Powder Diffraction Data ◽  
Powder Diffraction File ◽  
X Ray ◽  
Dimensional Network ◽  
Acid Proton

The crystal structure of cefprozil monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Cefprozil monohydrate crystallizes in space group P21 (#4) with a = 11.26513(6), b = 11.34004(5), c = 14.72649(11) Å, β = 90.1250(4)°, V = 1881.262(15) Å3, and Z = 4. Although a reasonable fit was obtained using an orthorhombic model, closer examination showed that many peaks were split and/or had shoulders, and thus the true symmetry was monoclinic. DFT calculations revealed that one carboxylic acid proton moved to an amino group. The structure thus contains one ion pair and one pair of neutral molecules. This protonation was confirmed by infrared spectroscopy. There is an extensive array of hydrogen bonds resulting in a three-dimensional network. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

Powder diffraction data of two tricydic diazonia diiodide salts used in silver iodide solid electrolytes

1993 ◽  
Vol 8 (3) ◽  
pp. 175-179
Author(s):  
J. Estienne ◽  
O. Cerclier ◽  
J. J. Rosenberg
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Silver Iodide ◽  
Solid Electrolytes ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Organic Salts ◽  
X Ray ◽  
Structure Determinations

Indexed X-ray powder diffraction data are reported for two organic salts with carbon rings having two quaternary nitrogens: diazonia-6,9 dispiro [5.2.5.2] hexadecane and diazonia-6,9 dispiro [5.2.5.3] heptadecane diiodides. For these compounds, which give solid electrolytes when associated with AgI, powder diffraction diagrams calculated by the Rietveld method from single crystal structure determinations are presented and are compared to the experimental diffraction data.

A Rietveld tutorial—Mullite

2009 ◽  
Vol 24 (4) ◽  
pp. 351-361 ◽  
Author(s):  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Rietveld Method ◽  
Amorphous Material ◽  
Thought Processes ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Bulk Chemical ◽  
The Common ◽  
Variable Stoichiometry

The crystal structure of the mullite in a commercial material was refined by the Rietveld method using laboratory X-ray powder diffraction data. In this one refinement, most of the common challenges—including variable stoichiometry (partially occupied sites), multiple impurity phases, amorphous material, constraints, restraints, correlation, anisotropic profiles, microabsorption, and contamination during grinding—are encountered and the thought processes during the refinement are described step-by-step. Interpretation of the refinements includes bulk chemical analysis, chemical composition of the mullite, assessment of the geometry, bond valence sums, the displacement coefficients, crystallite size and microstrain, comparison to similar structures to assess chemical reasonableness, and the nature of the amorphous phase.

Cristobalite-Related Phases in the NaAlO2–NaAlSiO4 System. II. A Commensurately Modulated Cubic Structure

1998 ◽  
Vol 54 (5) ◽  
pp. 547-557 ◽  
Author(s):  
R. L. Withers ◽  
J. G. Thompson ◽  
A. Melnitchenko ◽  
S. R. Palethorpe
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Tetrahedral Framework ◽  
X Ray ◽  
Sodium Aluminosilicate ◽  
Vacancy Ordering ◽  
Cubic Structure

The crystal structure of a new cubic cristobalite-related sodium aluminosilicate Na1.45Al1.45Si0.55O4 [P213, a = 14.553 (1) Å] has been modelled using a modulation wave approach and the model tested against X-ray powder diffraction data using the Rietveld method. Owing to there being 64 independent positional parameters and eight independent Na sites, refinement of the tetrahedral framework atom positions and Na occupancies was not possible. The framework was modelled successfully in terms of q 1 = 1\over 4〈020〉_p^*-type (p = parent) modulation waves with the requirement that the MO4 (M = Al0.725Si0.275) tetrahedra be as close to regular as possible. Na/vacancy ordering was modelled successfully in terms of q 2 = 1\over 4〈220〉_p^* modulation waves. Only the Na-atom positions were refined. The significance of this unique modulated cubic cristobalite-related structure and the possible insight it provides to understanding β-cristobalite are discussed.

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