Theoretical and Experimental Techniques for the Determination of X-ray Anomalous Dispersion Corrections

Theoretical and experimental techniques for the determination of the X-ray anomalous dispersion corrections f'(w, LI) and fl/(w, LI) are discussed. The results of experiments on metallic, ionic and covalently bonded materials typified by copper and nickel, lithium fluoride, and silicon respectively are compared with the theoretical predictions. Attention is drawn to deficiencies in both the experimental and the theoretical approaches.

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Determination of the Height of Hard X-Ray Sources in the Solar Atmosphere by Measurement of Photospheric Albedo Photons

Symposium - International Astronomical Union ◽

10.1017/s0074180900071746 ◽

1975 ◽

Vol 68 ◽

pp. 239-241

Author(s):

John C. Brown ◽

H. F. Van Beek

Keyword(s):

Solar Atmosphere ◽

The Other ◽

X Ray ◽

Theoretical Predictions ◽

Source Models ◽

The One

SummaryThe importance and difficulties of determining the height of hard X-ray sources in the solar atmosphere, in order to distinguish source models, have been discussed by Brown and McClymont (1974) and also in this Symposium (Brown, 1975; Datlowe, 1975). Theoretical predictions of this height, h, range between and 105 km above the photosphere for different models (Brown and McClymont, 1974; McClymont and Brown, 1974). Equally diverse values have been inferred from observations of synchronous chromospheric EUV bursts (Kane and Donnelly, 1971) on the one hand and from apparently behind-the-limb events (e.g. Datlowe, 1975) on the other.

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Crystal structure determination of solar cell materials: Cu2ZnSnS4 thin films using X-ray anomalous dispersion

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2012.01.134 ◽

2012 ◽

Vol 524 ◽

pp. 22-25 ◽

Cited By ~ 35

Author(s):

Hiroshi Nozaki ◽

Tatsuo Fukano ◽

Shingo Ohta ◽

Yoshiki Seno ◽

Hironori Katagiri ◽

...

Keyword(s):

Crystal Structure ◽

Thin Films ◽

Solar Cell ◽

Structure Determination ◽

Anomalous Dispersion ◽

Crystal Structure Determination ◽

X Ray

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Experimental determination of electric-field-induced differences in structure-factor phases of the order of 2%

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767399009782 ◽

1999 ◽

Vol 55 (6) ◽

pp. 1034-1037 ◽

Cited By ~ 3

Author(s):

J. Stahn ◽

A. Pucher ◽

U. Pietsch ◽

J. Zellner ◽

E. Weckert

Keyword(s):

Electric Field ◽

Structure Factor ◽

Phase Variation ◽

Bonded Materials ◽

Charge Model ◽

Covalently Bonded ◽

Phase Variations ◽

Bond Charge ◽

Semi Empirical

In order to understand the induced electron-density response of covalently bonded materials to an externally applied electric field, the change of structure-factor phases of several weak reflections of GaAs has been measured by three-beam interferences. Using a modulation technique, phase variations of the order of 1° for a field strength of 1 kV mm−1 were determined. Although the statistics of these first experiments are rather poor, the experiment verifies qualitatively the predictions of a semi-empirical bond-charge model. The measured phase variation is the smallest value determined up to now.

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Determination of the absolute steric course of a solid-state photorearrangement by anomalous dispersion x-ray crystallography

Journal of the American Chemical Society ◽

10.1021/ja00195a066 ◽

1989 ◽

Vol 111 (13) ◽

pp. 4985-4986 ◽

Cited By ~ 14

Author(s):

Miguel Garcia-Garibay ◽

John R. Scheffer ◽

James Trotter ◽

Fred Wireko

Keyword(s):

Solid State ◽

Anomalous Dispersion ◽

X Ray ◽

X Ray Crystallography ◽

The Absolute

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Expanded potential of seleno-carbohydrates as a molecular tool for X-ray structural determination of a carbohydrate–protein complex with single/multi-wavelength anomalous dispersion phasing

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2014.02.023 ◽

2014 ◽

Vol 22 (7) ◽

pp. 2090-2101 ◽

Cited By ~ 19

Author(s):

Tatsuya Suzuki ◽

Hisayoshi Makyio ◽

Hiromune Ando ◽

Naoko Komura ◽

Masanori Menjo ◽

...

Keyword(s):

Protein Complex ◽

Anomalous Dispersion ◽

Structural Determination ◽

X Ray ◽

Molecular Tool ◽

Multi Wavelength

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ChemInform Abstract: Determination of the Absolute Steric Course of a Solid-State Photorearrangement by Anomalous Dispersion X-Ray Crystallography.

ChemInform ◽

10.1002/chin.198940059 ◽

1989 ◽

Vol 20 (40) ◽

Author(s):

M. GARCIA-GARIBAY ◽

J. R. SCHEFFER ◽

J. TROTTER ◽

F. WIREKO

Keyword(s):

Solid State ◽

Anomalous Dispersion ◽

X Ray ◽

X Ray Crystallography ◽

The Absolute

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Diffuse scattering from microstructures and mesostructures

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.2005.220.12.994 ◽

2005 ◽

Vol 220 (12) ◽

Author(s):

Stuart A. Hayward ◽

Ekhard K. H. Salje

Keyword(s):

Diffuse Scattering ◽

Experimental Methods ◽

Incident Radiation ◽

Careful Attention ◽

X Ray Diffraction ◽

Elastic Materials ◽

X Ray ◽

Weak Intensity ◽

Theoretical Predictions

AbstractMesoscopic features, such as thick twin walls, surface relaxations, or haloes around metamict regions in crystals have a lengthscale of the order of 1–100 Å. Such features are studied experimentally using diffuse scattering signals; either between pairs of twin-related Bragg peaks (for twin walls) or around Bragg peaks (for features such as metamict haloes). Study of such features by X-ray diffraction has a number of advantages over the use of electron microscopy, many related to the reduced need for invasive sample preparation. The weak intensity of diffraction from mesostructures requires careful attention to experimental design, either using extremely strong incident radiation, or optimised collection geometry. Measurements of twin wall widths in a range of ferroelastic and co-elastic materials and minerals and their temperature dependence are reviewed, and found to be consistent with theoretical predictions and the results of other experimental methods. Determination of the size of metamict regions in zircon from diffuse scattering agree with the results of microscopy experiments.

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Synthesis of seleno-fucose compounds and their application to the X-ray structural determination of carbohydrate-lectin complexes using single/multi-wavelength anomalous dispersion phasing

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2016.12.021 ◽

2017 ◽

Vol 25 (3) ◽

pp. 1132-1142 ◽

Cited By ~ 4

Author(s):

Junpei Shimabukuro ◽

Hisayoshi Makyio ◽

Tatsuya Suzuki ◽

Yosuke Nishikawa ◽

Masato Kawasaki ◽

...

Keyword(s):

Anomalous Dispersion ◽

Structural Determination ◽

X Ray ◽

Multi Wavelength

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Ab initio cluster calculations of defects in solids

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1992.0107 ◽

1992 ◽

Vol 341 (1661) ◽

pp. 351-360 ◽

Cited By ~ 48

Keyword(s):

Density Functional ◽

Local Density ◽

Rapid Determination ◽

Molecular Solids ◽

Unusual Structure ◽

Bonded Materials ◽

Ionic Systems ◽

Covalently Bonded ◽

Local Density Functional Theory

A method based on local density functional theory is described which leads to the rapid determination of the structure, vibrational and electronic properties of clusters as large as 100-150 atoms. The technique is particularly suitable for molecular solids, covalently bonded materials where the clusters are terminated by hydrogen, and to ionic systems where the termination consists of a set of distributed charges. The strengths and weaknesses of the method are detailed together with an application to the interstitial carbon-oxygen complex in silicon where oxygen is found to be over-coordinated. The good agreement obtained for the vibrational modes of the complex lends support to the unusual structure found.

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