Local structure in the paraelectric phase ofCd2Nb2O7determined from x-ray diffuse scattering, by means ofab initiomolecular dynamics and Monte Carlo modeling

2010 ◽  
Vol 81 (1) ◽  
Author(s):  
Marek Paściak ◽  
Marek Wołcyrz ◽  
Adam Pietraszko ◽  
Stefano Leoni
Keyword(s):  
Monte Carlo ◽  
Local Structure ◽  
Diffuse Scattering ◽  
Paraelectric Phase ◽  
Monte Carlo Modeling ◽  
X Ray

Polymorphism and Polytypism of α-LiNH4SO4 Crystals. Monte Carlo Modeling Based on X-ray Diffuse Scattering

2014 ◽  
Vol 14 (11) ◽  
pp. 5784-5793 ◽  
Author(s):  
Dorota Komornicka ◽  
Marek Wołcyrz ◽  
Adam Pietraszko
Keyword(s):  
Monte Carlo ◽  
Diffuse Scattering ◽  
Monte Carlo Modeling ◽  
X Ray

Diffuse X-ray scattering from tiny sample volumes

2005 ◽  
Vol 220 (12) ◽  
Author(s):  
Gene E. Ice ◽  
Rozaliya I. Barabash ◽  
Wenjun Liu
Keyword(s):  
Local Structure ◽  
Diffuse Scattering ◽  
High Performance ◽  
Sensitive Area ◽  
X Ray ◽  
X Ray Scattering ◽  
Defect Content ◽  
Ray Scattering

AbstractThe emergence of intense synchrotron X-ray sources, efficient focusing optics and high-performance X-ray sensitive area detectors allows for measurements of diffuse scattering from cubic micron-scale sample vol umes. Here we present an experiment that illustrates methods for studying the local structure and defect content of tiny sample volumes. In the experiment, an X-ray microbeam illuminating about ∼5 μm

Crystal structure and enantiomeric layer disorder of a copper(I) nitrate π-coordination compound

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Dorota A. Kowalska ◽  
Vasyl Kinzhybalo ◽  
Yuriy I. Slyvka ◽  
Marek Wołcyrz
Keyword(s):  
Coordination Compound ◽  
Local Structure ◽  
Diffuse Scattering ◽  
Weak Interactions ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Solution ◽  
First Time ◽  
Layer Disorder

The novel π-coordination compound [CuI(m-dmphast)NO3], where m-dmphast = 5-(allylthio)-1-(3,5-dimethylphenyl)-1H-tetrazole, is characterized using single-crystal X-ray diffraction and crystallizes in a noncentrosymmetric space group. Additionally, for the first time in this group of materials, the streaks of X-ray diffuse scattering in the reciprocal space sections were observed and described. This gave the possibility for a deeper insight into the local structure of the title compound. The conjecture about the origin of diffuse scattering was derived from average structure solution. It was then confirmed using the local structure modelling. The extended [Cu(m-dmphast)NO3]∞ chains, connected by weak interactions, produce layers which can exist in two enantiomeric forms, one of which predominates.

X-ray diffuse scattering from HMTA: analysis via a Monte Carlo model

2008 ◽  
Vol 64 (4) ◽  
pp. 456-465 ◽  
Author(s):  
D. J. Goossens ◽  
A. P. Heerdegen ◽  
T. R. Welberry
Keyword(s):  
Monte Carlo ◽  
Azelaic Acid ◽  
Diffuse Scattering ◽  
Cross Correlation ◽  
Monte Carlo Model ◽  
Limited Range ◽  
Thermally Induced ◽  
X Ray ◽  
Zero Correlation ◽  
Average Position

Hexamethylenetetramine (HMT, C6H12N4, also referred to as urotropin) and azelaic acid [A, HOOC—(CH2)7—COOH] form a co-crystal or adduct (HMTA, also referred to as urotropin azelate) which exhibits several structural phases as a function of temperature. At room temperature, the structure is orthorhombic, but shows substantial disorder. Here, this disorder is explored by analyzing the diffuse scattering from single crystals of HMTA via Monte Carlo simulation. The disorder is in part occupational, with two orientations of azelaic acid occurring, and in part thermally induced, which is to say dynamic. The occupational disorder can be thought of as a combination of limited-range in-plane (bc plane) negative correlations combined with effectively zero correlation between planes (along a), rather like stacking faults. Size effect, the cross-correlation between molecular orientation and displacement from average position, is required to reproduce the observed diffuse scattering.

X-ray diffraction, neutron scattering and EXAFS spectroscopy of monoclinic zirconia: analysis by Rietveld refinement and reverse Monte Carlo simulations

2002 ◽  
Vol 35 (4) ◽  
pp. 434-442 ◽  
Author(s):  
Markus Winterer ◽  
Robert Delaplane ◽  
Robert McGreevy
Keyword(s):  
Monte Carlo ◽  
Neutron Scattering ◽  
Rietveld Refinement ◽  
Local Structure ◽  
Exafs Spectroscopy ◽  
Scattering Data ◽  
Accurate Information ◽  
Reverse Monte Carlo ◽  
Monoclinic Zirconia ◽  
X Ray

Extended X-ray absorption fine structure (EXAFS) and neutron scattering data from monoclinic zirconia are analysed independently and simultaneously by reverse Monte Carlo (RMC) modelling. X-ray and neutron powder diffraction data are analysed by Rietveld refinement. The results are compared with respect to the local structure around the zirconium cations. Monoclinic zirconia was chosen as a model system for the comparison of structural information obtained by EXAFS spectroscopy and scattering methods because it is crystalline but also has some local disorder. In the case of zirconia, analysis of EXAFS spectra by RMC modelling results in reliable and accurate information on the local structure, consistent with neutron scattering and diffraction experiments.

scholarly journals Reverse Monte Carlo modeling of the neutron and X-ray diffraction data for new chalcogenide Ge–Sb–S(Se)–Te glasses

2013 ◽  
Vol 74 (10) ◽  
pp. 1355-1362 ◽  
Author(s):  
M. Fabian ◽  
E. Svab ◽  
V. Pamukchieva ◽  
A. Szekeres ◽  
K. Todorova ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Diffraction Data ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
Monte Carlo Modeling ◽  
X Ray
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