NanoPDF64: software package for theoretical calculation and quantitative real-space analysis of powder diffraction data of nanocrystals

2017 ◽  
Vol 50 (6) ◽  
pp. 1821-1829 ◽  
Author(s):  
Kazimierz Skrobas ◽  
Svitlana Stelmakh ◽  
Stanislaw Gierlotka ◽  
Bogdan F. Palosz
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Analytical Formula ◽  
Real Space ◽  
Distribution Functions ◽  
Powder Diffraction Data ◽  
Space Analysis ◽  
Atomic Vibrations ◽  
Hexagonal Close Packed Structure ◽  
Diffraction Patterns

NanoPDF64is a tool designed for structural analysis of nanocrystals based on examination of powder diffraction data with application of real-space analysis. The program allows for fast building of models of nanocrystals consisting of up to several hundred thousand atoms with either cubic or hexagonal close packed structure. The nanocrystal structure may be modified by introducing stacking faults, density modulation waves (i.e.the core–shell model) and thermal atomic vibrations. The program calculates diffraction patterns and, by Fourier transform, the reduced pair distribution functionsG(r) for the models. ExperimentalG(r)s may be quantitatively analyzed by least-squares fitting with an analytical formula.

Challenging structure determination from powder diffraction data: two pharmaceutical salts and one cocrystal with Z′ = 2

2019 ◽  
Vol 234 (4) ◽  
pp. 257-268 ◽  
Author(s):  
Carina Schlesinger ◽  
Michael Bolte ◽  
Martin U. Schmidt
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Real Space ◽  
Powder Diffraction Data ◽  
The Real ◽  
Pharmaceutical Salts ◽  
Structure Solution ◽  
Space Method

Abstract Structure solution of molecular crystals from powder diffraction data by real-space methods becomes challenging when the total number of degrees of freedom (DoF) for molecular position, orientation and intramolecular torsions exceeds a value of 20. Here we describe the structure determination from powder diffraction data of three pharmaceutical salts or cocrystals, each with four molecules per asymmetric unit on general position: Lamivudine camphorsulfonate (1, P 21, Z=4, Z′=2; 31 DoF), Theophylline benzamide (2, P 41, Z=8, Z′=2; 23 DoF) and Aminoglutethimide camphorsulfonate hemihydrate [3, P 21, Z=4, Z′=2; 31 DoF (if the H2O molecule is ignored)]. In the salts 1 and 3 the cations and anions have two intramolecular DoF each. The molecules in the cocrystal 2 are rigid. The structures of 1 and 2 could be solved without major problems by DASH using simulated annealing. For compound 3, indexing, space group determination and Pawley fit proceeded without problems, but the structure could not be solved by the real-space method, despite extensive trials. By chance, a single crystal of 3 was obtained and the structure was determined by single-crystal X-ray diffraction. A post-analysis revealed that the failure of the real-space method could neither be explained by common sources of error such as incorrect indexing, wrong space group, phase impurities, preferred orientation, spottiness or wrong assumptions on the molecular geometry or other user errors, nor by the real-space method itself. Finally, is turned out that the structure solution failed because of problems in the extraction of the integrated reflection intensities in the Pawley fit. With suitable extracted reflection intensities the structure of 3 could be determined in a routine way.

Powder-diffraction data for several solid solutions with the compositions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3

1995 ◽  
Vol 10 (4) ◽  
pp. 296-299 ◽  
Author(s):  
S. T. Misture ◽  
C. Park ◽  
R. L. Snyder ◽  
B. Jobst ◽  
B. Seebacher
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
High Temperature Superconductors ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Diffraction Patterns

Several compositions of the solid solutions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3, both of which are found as minor phases in the high-temperature superconductors, were prepared by solid-state reaction. X-ray powder-diffraction patterns for three compositions of (CaxSr1−x)CuO2 and two for (CaxSr1−x)2CuO3 are presented.

Update in a Rietveld analysis program for x-ray powder spectro-diffractometry

2003 ◽  
Vol 18 (1) ◽  
pp. 32-35 ◽  
Author(s):  
Yanan Xiao ◽  
Fujio Izumi ◽  
Timothy Graber ◽  
P. James Viccaro ◽  
Dale E. Wittmer
Keyword(s):  
Computer Program ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Analysis ◽  
Anomalous Scattering ◽  
Analysis Program ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Synchrotron Light ◽  
Diffraction Patterns

A computer program for refining anomalous scattering factors using x-ray powder diffraction data was revised on the basis of the latest version of a versatile pattern-fitting system, RIETAN-2000. The effectiveness of the resulting program was confirmed by applying it to simulated and measured powder-diffraction patterns of Mn3O4 taken at a synchrotron light source.

X-ray powder diffraction data for compound DyNiSn

1997 ◽  
Vol 12 (3) ◽  
pp. 134-135
Author(s):  
Liangqin Nong ◽  
Lingmin Zeng ◽  
Jianmin Hao
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Diffraction Patterns

The compound DyNiSn has been studied by X-ray powder diffraction. The X-ray diffraction patterns for this compound at room temperature are reported. DyNiSn is orthorhombic with lattice parameters a=7.1018(1) Å, b=7.6599(2) Å, c=4.4461(2) Å, space group Pna21 and 4 formula units of DyNiSn in unit cell. The Smith and Snyder Figure-of-Merit F30 for this powder pattern is 26.7(0.0178,63).

X-Ray Powder Diffraction Data and Crystal Refinement of a New Compound AlCrNi3Pr

2016 ◽  
Vol 850 ◽  
pp. 3-7
Author(s):  
Shu Hui Liu ◽  
Liu Qing Liang ◽  
Chang Sheng Qin ◽  
De Gui Li ◽  
Ling Min Zeng ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Structure Type ◽  
Hexagonal Structure ◽  
Powder Diffraction Data ◽  
Tungsten Electrode ◽  
X Ray ◽  
Diffraction Patterns

Rare earth-transition metal (R-T) intermetallics have been well used because of their excellent properties. The X-ray diffraction patterns of many new phases in the R-T system have not been extensively studied. A new compound AlCrNi3Pr was prepared by arc melting using non-consumable tungsten electrode under argon atmosphere, and then annealed at 1023K for 30 days. The X-ray powder diffraction data of AlCrNi3Pr was collected on a Rigaku SmartLab X-ray powder diffractometer. The powder patterns of the compound were indexed, and the structure refinement by using Rietveld method indicated that the AlCrNi3Pr compound crystallized in the hexagonal structure, space group P6/mmm (No.191) with PrNi5 structure type, a=b=5.0553(9) Ǻ, c=4.0763(6) Ǻ, V=90.22Ǻ3, Z=1, ρx=7.288g cm-3, the Smith–Snyder FOM F30=279.1(0.0044, 32) and the intensity ratio RIR=1.23.

X-ray powder diffraction data of anilinium trimolybdate tetrahydrate and anilinium trimolybdate dihydrate

1999 ◽  
Vol 14 (4) ◽  
pp. 280-283 ◽  
Author(s):  
A. Rafalska-Łasocha ◽  
W. Łasocha ◽  
M. Michalec
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns

The X-ray powder diffraction patterns of anilinium trimolybdate tetrahydrate, (C6H5NH3)2Mo3O10·4H2O, and anilinium trimolybdate dihyhydrate, (C6H5NH3)2Mo3O10·2H2O, have been measured in room temperature. The unit cell parameters were refined to a=11.0670(7) Å, b=7.6116(8) Å, c=25.554(3) Å, space group Pnma(62) and a=17.560(2) Å, b=7.5621(6) Å, c=16.284(2) Å, β=108.54(1)°, space group P21(4) or P21/m(11) for orthorhombic anilinium trimolybdate tetrahydrate and monoclinic anilinium trimolybdate dihydrate, respectively.

Powder Diffraction Data of Some Acentric Tartrates and Tartrato-Antimonates

1991 ◽  
Vol 6 (2) ◽  
pp. 107-110
Author(s):  
Markus Garsche ◽  
Ekkehart Tillmanns ◽  
Thomas Bauer ◽  
Reinhard X. Fischer ◽  
Ladislav Bohaty
Keyword(s):  
Aqueous Solutions ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Optical Effects ◽  
Diffraction Patterns

AbstractSix acentric tartrates and tartrato-antimonates have been investigated by means of X-ray powder diffraction. Single crystals were obtained by evaporation from aqueous solutions. The compounds have attracted attention because of their electrostrictive and electro-optical effects. Complete crystal data for the six compounds are reported. X-ray powder diffraction patterns for Rb2C4H4O6 and Ca [Sb2{C4H2O6}2]·2H2O are given.

Structures of six industrial benzimidazolone pigments from laboratory powder diffraction data

2009 ◽  
Vol 65 (2) ◽  
pp. 200-211 ◽  
Author(s):  
Jacco van de Streek ◽  
Jürgen Brüning ◽  
Svetlana N. Ivashevskaya ◽  
Martin Ermrich ◽  
Erich F. Paulus ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Real Space ◽  
Powder Diffraction Data ◽  
Intermolecular Hydrogen Bonds ◽  
Rietveld Refinements ◽  
Hydrogen Bonding Pattern ◽  
Β Phase ◽  
Α Phase

The crystal structures of six industrially produced benzimidazolone pigments [Pigment Orange 36 (β phase), Pigment Orange 62, Pigment Yellow 151, Pigment Yellow 154 (α phase), Pigment Yellow 181 (β phase) and Pigment Yellow 194] were determined from laboratory X-ray powder diffraction data by means of real-space methods using the programs DASH and MRIA, respectively. Subsequent Rietveld refinements were carried out with TOPAS. The crystal phases correspond to those produced industrially. Additionally, the crystal structures of the non-commercial compound `BIRZIL' (a chloro derivative of Pigment Yellow 194) and of a dimethylsulfoxide solvate of Pigment Yellow 154 were determined by single-crystal structure analyses. All eight crystal structures are different; the six industrial pigments even exhibit five different hydrogen-bond topologies. Apparently, the good application properties of the benzimidazolone pigments are not the result of one specific hydrogen-bonding pattern, but are the result of a combination of efficient molecular packing and strong intermolecular hydrogen bonds.

X-ray powder diffraction studies of fibrillar zinc trimolybdates ZnMo3O10·nH2O (n=3.75,5,10)

1999 ◽  
Vol 14 (4) ◽  
pp. 276-279
Author(s):  
Wiesław Łasocha ◽  
Wiesław Surga ◽  
Alicja Rafalska-Łasocha
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Lattice Parameters ◽  
Fiber Axis ◽  
Powder Diffraction Data ◽  
Parallel Fibers ◽  
X Ray ◽  
Space Groups ◽  
Diffraction Patterns

The X-ray powder diffraction data of polycrystalline fibrillar zinc trimolybdates ZnMo3O10·3.75H2O, ZnMo3O10·5H2O, and ZnMo3O10·10H2O, are reported. An uncommon diffraction pattern was recorded in the case of the “wet fibers” of ZnMo3O10·10H2O, which could be indexed assuming a model of parallel fibers with translation disorder along the fiber axis. The powder diffraction patterns, lattice parameters, space groups, and other data describing these compounds are presented in this paper.© 1999 International Centre for Diffraction Data.

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