X-ray powder reference patterns of the Fe(Sb2+xTe1−x) skutterudites for thermoelectric applications

2014 ◽  
Vol 29 (3) ◽  
pp. 260-264 ◽  
Author(s):  
W. Wong-Ng ◽  
J.A. Kaduk ◽  
G. Tan ◽  
Y. Yan ◽  
X. Tang
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Bond Distance ◽  
Lattice Parameter ◽  
Covalent Radius ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Cell Parameters ◽  
Xrd Patterns

The crystal structure and powder X-ray diffraction (XRD) patterns for three skutterudite samples, Fe(Sb2+xTe1−x), x = 0.05, 0.10, 0.20, have been determined. These compounds crystallize in the cubic space group $Im\bar 3$. Te was found to randomly substitute in the Sb site. Because of the fact the covalent radius of Sb is greater than that of Te, a trend of increasing lattice parameter has been observed as the x value in Fe(Sb2+xTe1−x) increases [cell parameters range from 9.10432(4) to 9.11120(3) Å for x = 0.0 to 0.2, respectively]. The Fe–Sb/Te bond distance also increases progressively [from 2.5358(4) to 2.5388(4) Å] as the Te content decreases. While average Sb/Te–Sb/Te distances in the four-membered rings are similar in these three compounds, the average Sb/Te–Sb/Te edge distances in the octahedral framework increase progressively from 3.5845(12) to 3.5900(13) Å. Reference XRD patterns of these three phases have been prepared to be included in the Powder Diffraction File (PDF).

Powder X-ray diffraction of pazopanib hydrochloride Form 1, C21H24N7O2SCl

2021 ◽  
pp. 1-3
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Lattice Energy ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Functional Theory ◽  
X Ray

The crystal structure of pazopanib hydrochloride Form 1 has been refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Pazopanib hydrochloride crystallizes in space group P-1 (#2) with a = 8.45008(6), b = 8.71310(12), c = 16.05489(35) Å, α = 79.5996(9), β = 86.4784(5), γ = 87.3764(3)°, V = 1159.724(9) Å3, and Z = 2. The crystal structure is essentially identical to that of CSD Refcode CEVYEK. There are four strong N–H⋯Cl hydrogen bonds to the chloride anion. Several additional weaker N–H⋯Cl and C–H⋯Cl hydrogen bonds are also present. A variety of C–H⋯O, C–H⋯N, and N–H⋯S hydrogen bonds also contribute to the lattice energy. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

An X-ray powder diffraction study of the spin-crossover transition and structure of bis(2,6-dipyrazol-1-ylpyrazine)iron(II) perchlorate

2004 ◽  
Vol 60 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Victoria A. Money ◽  
Ivana Radosavljevic Evans ◽  
Jerome Elhaïk ◽  
Malcolm A. Halcrow ◽  
Judith A. K. Howard
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Spin Crossover ◽  
Spin Transition ◽  
High Spin State ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Crossover Transition

The crystal structure of the iron(II) spin-crossover compound [Fe(C10H8N6)2](ClO4)2 in the high-spin state has been solved from powder X-ray diffraction data using the DASH program and refined using Rietveld refinement. The thermal spin transition has been monitored by following the change in unit-cell parameters with temperature. The title compound has been found to undergo a crystallographic phase change, involving a doubling of the crystallographic a axis, on undergoing the spin transition.

Powder X-ray diffraction of oseltamivir phosphate (Tamiflu®), C16H31N2O8P

2020 ◽  
Vol 35 (3) ◽  
pp. 216-218
Author(s):  
Ryan L. Hodge ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Oseltamivir Phosphate ◽  
Phosphate Groups

The crystal structure of oseltamivir phosphate has been refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Oseltamivir phosphate crystallizes in space group P21212 (#18) with a = 24.0079(3), b = 24.6716(2), c = 7.45254(5) Å, V = 4414.24(5) Å3 at 295 K, and Z = 8. Prominent in the crystal structure are hydrogen bonds between the phosphate groups and the ammonium groups of the oseltamivir cations. The strong hydrogen bonds link the cations and the anions into columns parallel to the c-axis, with van der Waals interactions between the columns. Thermal expansion between 120 and 295 K is anisotropic. The powder pattern is included in the Powder Diffraction File™ as entry 00-068-1107.

Crystal structures and reference X-ray powder diffraction patterns of Sr4−xCaxPb2O8 (x=1,2,3)

1998 ◽  
Vol 13 (4) ◽  
pp. 232-240 ◽  
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
W. Greenwood
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Alkaline Earth ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Diffraction Patterns

The crystal structure of the solid solution alkaline earth plumbate phase Sr4−xCaxPb2O8 was investigated using the X-ray Rietveld technique for x=1, 2, and 3. The lattice parameters a, b, c, and V were found to decrease linearly as the Sr at site 4h was replaced by Ca. The structure features chains of edge-sharing PbO6 octahedra, linked by seven-coordinated (Ca/Sr)–O monocapped trigonal prisms. The structure is similar to that of Pb3O4, which can be reformulated as Pb2IIPbIVO4. X-ray diffraction patterns for the solid solution members SrCa3Pb2O8, Sr2Ca2Pb2O8, and Sr3CaPb2O8 were prepared for inclusion in the Powder Diffraction File.

Powder X-ray diffraction of varenicline hydrogen tartrate Form B (Chantix®), (C13H14N3)(HC4H4O6)

2021 ◽  
pp. 1-3
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Space Group ◽  
X Ray

The crystal structure of varenicline hydrogen tartrate Form B (Chantix®) has been refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Varenicline hydrogen tartrate Form B crystallizes in space group P212121 (#19) with a = 7.07616(2), b = 7.78357(2), c = 29.86149(7) Å, V = 1644.706(6) Å3, and Z = 4. The hydrogen bonds were identified and quantified. Hydrogen bonds link the cations and anions in zig-zag chains along the b-axis. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

Evaluating experimental methods and techniques in X-ray diffraction using 280 000 data sets in the Powder Diffraction File

2004 ◽  
Vol 19 (1) ◽  
pp. 20-25 ◽  
Author(s):  
T. G. Fawcett ◽  
S. N. Kabbekodu ◽  
J. Faber ◽  
F. Needham ◽  
F. McClune
Keyword(s):  
Powder Diffraction ◽  
Large Population ◽  
Evaluation Criteria ◽  
Calculated Data ◽  
Quality Criteria ◽  
Experimental Methods ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Cell Parameters

Release 2003 of the Powder Diffraction File (PDF) contains ∼280 000 unique entries organized in a series of tables in a relational database format. The PDF is available in two products, PDF-4/Full File and PDF-4/Organics, which allow users to access and query over 150 million filled entry fields. An editorial database is used to generate the commercial products that contain tables of experimental details and statistical evaluation criteria used by the editors to evaluate quality and determine quality marks for each entry in the PDF. This editorial database has nearly doubled the searchable entry fields. This database was mined to evaluate experimental methods in X-ray diffraction. Both experimental powder diffraction data and data calculated from predominantly single crystal X-ray structural analyses were assigned statistical quality criteria. For experimental powder data, the average delta two theta values for all d-spacings in the entry set were used. Calculated data were evaluated using R factor values as the primary quality criteria. A Quality Index, which measures the errors in refined unit cell parameters divided by the magnitude of the cell parameter, can be used to compare all types of data. Experimental variables were then analyzed versus these criteria. Variables include optic configuration, (i.e., Seeman–Bohlin, Guinier, Debye–Scherrer), use of internal and external standards, use of monochromators, wavelength divergence, wavelength selection, equipment radius, specimen transparency, and specimen absorption. This study significantly differs from prior round robin analyses in that the use of the database allows us to study very large population sets for every variable analyzed.

Crystal structure of Ca1−xSrxZr4(PO4)6 (0≤x≤1)

2004 ◽  
Vol 19 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Werner Fischer ◽  
Lorenz Singheiser ◽  
Debabrata Basu ◽  
Amit Dasgupta
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
High Temperature ◽  
Structural Transformation ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of several compounds of Ca1−xSrxZr4(PO4)6 ceramics has been investigated by X-ray powder diffraction at room temperature. All compounds form a solid solution with a unique unit cell. While the lattice parameter a of the hexagonal unit cell decreases of about 0.9% with increasing Sr content only slightly, it considerably elongates in c direction (2.8%). No structural transformation has been observed by high-temperature X-ray diffraction up to 1000 °C.

scholarly journals Synchrotron X-ray diffraction study of double perovskites Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu)

2018 ◽  
Vol 33 (4) ◽  
pp. 279-286
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
S. H. Lapidus ◽  
L. Ribaud ◽  
S. P. Diwanji
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Powder Diffraction ◽  
Double Perovskite ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Analysis Technique ◽  
Diffraction Patterns

A series of double-perovskite oxides, Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu) were prepared and their crystal structure and powder diffraction reference patterns were determined using the Rietveld analysis technique. The crystal structure of each of the Sr2RNbO6 phase is reported in this paper. The R = Gd, Ho, and Lu samples were studied using synchrotron radiation, while R = Sm, Dy, Y, and Tm samples were studied using laboratory X-ray diffraction. Members of Sr2RNbO6 are monoclinic with a space group of P21/n and are isostructural with each other. Following the trend of “lanthanide contraction”, from R = Sm to Lu, the lattice parameters “a” of these compounds decreases from 5.84672(10) to 5.78100(3) Å, b from 5.93192(13) to 5.80977(3) Å, c from 8.3142(2) to 8.18957(5) Å, and V decreases from 288.355(11) to 275.057(2) Å3. In this double-perovskite series, the R3+ and Nb5+ ions are structurally ordered. The average Nb–O bond length is nearly constant, while the average R–O bond length decreases with the decreasing ionic radius of R3+. Powder diffraction patterns for these compounds have been submitted to the Powder Diffraction File (PDF).

An Application of Calculated X-Ray Diffraction Patterns in the Analysis of Reference Powder Data: Trivalent Metal Sulfates

1992 ◽  
Vol 7 (4) ◽  
pp. 215-218 ◽  
Author(s):  
Sidney S. Pollack ◽  
Gregory J. McCarthy ◽  
Jean M. Holzer
Keyword(s):  
Powder Diffraction ◽  
Structure Data ◽  
The Other ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Trivalent Metal ◽  
Powder Diffraction File ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns

AbstractPowder diffraction patterns have been calculated for nine isostructural rhombohedral M2(SO4)3 (M = Sc, Ti, V, Cr, Fe, Ga, Y, Rh, In) phases, and for four isostructural monoclinic M2(SO4)3 (M = V, Fe, In, Tl) phases. The pattern for monoclinic Fe2(SO4)3 is the first reported for this phase. Because structure data are available only for the two Fe2(SO4)3 polymorphs, the powder patterns of the other trivalent metal sulfates were approximated using the structure data of the isostructural Fe phases with the scattering factors and previously determined cell parameters of the various metal sulfates. These calculated patterns are termed an approximation by isostruduralism.The calculated patterns were used to evaluate reference powder data for these phases in the Powder Diffraction File (PDF). All but two of the PDF patterns were found to differ substantially from the calculated patterns in the stronger peaks used for identification, and to be missing weak peaks that may be confused for impurities during phase identification.

Powder X-ray diffraction of daclatasvir dihydrochloride Form N-2 (Daklinza®), C40H52N8O6Cl2

2021 ◽  
pp. 1-4
Author(s):  
Ryan L. Hodge ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Functional Theory ◽  
X Ray

The crystal structure of daclatasvir dihydrochloride Form N-2 (Daklinza®) has been refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Daclatasvir dihydrochloride, Form N-2, crystallizes in space group P1 (#1) with a = 7.54808 (15), b = 9.5566 (5), c = 16.2641 (11) Å, α = 74.0642 (24), β = 84.0026 (13), γ = 70.6322 (5)°, V = 1064.150(11) Å3, and Z = 1. The hydrogen bonds were identified and quantified. Strong N–H⋯Cl hydrogen bonds link the cations and anions in chains along the a-axis. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

Sign in / Sign up

Export Citation Format

Share Document