Scattering-matrix formulation of curved-wave multiple-scattering theory: Application to x-ray-absorption fine structure

1990 ◽  
Vol 41 (12) ◽  
pp. 8139-8149 ◽  
Author(s):  
J. J. Rehr ◽  
R. C. Albers
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Scattering Theory ◽  
Scattering Matrix ◽  
Matrix Formulation ◽  
Multiple Scattering Theory ◽  
X Ray ◽  
Absorption Fine ◽  
Theory Application ◽  
X Ray Absorption

Extended X-ray absorption fine structure and multiple-scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n(n= −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1-hexene)

2015 ◽  
Vol 22 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Weiwei Gu ◽  
Hongxin Wang ◽  
Kun Wang
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible ◽  
Edge Features ◽  
X Ray Absorption

A series of Ni dithiolene complexes Ni[S2C2(CF3)]2n(n= −2, −1, 0) (1,2,3) and a 1-hexene adduct Ni[S2C2(CF3)2]2(C6H12) (4) have been examined by NiK-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopies. Ni XANES for1–3reveals clear pre-edge features and approximately +0.7 eV shift in the NiK-edge position for `one-electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for1,2and3(2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ∼0.022 Å for each `one-electron' oxidation. The changes in NiK-edge energy positions and Ni—S distances are consistent with the `non-innocent' character of the dithiolene ligand. The Ni—C interactions at ∼3.0 Å are analyzed and the multiple-scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1-hexene adduct4presents no pre-edge feature, and its NiK-edge position shifts by −0.8 eV in comparison with its starting dithiolene complex3. Consistently, EXAFS also showed that the Ni—S distances in4elongate by ∼0.046 Å in comparison with3. The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π-electron density to the LUMO of3as suggested by UV/visible spectroscopy in the literature.

X -Ray Absorption Near Edge Structure (XANES) Calculations for the Amorphous Fe80B20- and Ni80B20-Alloys

1989 ◽  
Vol 44 (3) ◽  
pp. 189-194
Author(s):  
P. Kizler ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Multiple Scattering ◽  
Scattering Theory ◽  
Edge Structure ◽  
Multiple Scattering Theory ◽  
X Ray ◽  
Bond Angles ◽  
Complex Features ◽  
X Ray Absorption ◽  
Good Agreement

Xanes spectra of the amorphous Fe80B20- and Ni80B20-alloys have been investigated using the electron multiple scattering theory of Durham et al. The calculations were based on several models for the structure of amorphous Fe80B20 and Ni80B20. Very good agreement between theoretical and experimental XANES curves was met. Opposite to former expectations for obtaining information on bond angles by XANES, this study shows that XANES points to more complex features of the structure than can be expressed in terms of bond angles.

Br K-Edge X-ray Absorption Near Edge Structure Analyses of Bromine Residue Carbon Compounds Using Full Multiple-Scattering Theory

2005 ◽  
Vol 44 (6A) ◽  
pp. 4073-4079 ◽  
Author(s):  
Kanae Uno ◽  
Yasuharu Notoya ◽  
Takashi Fujikawa ◽  
Hidetaka Yoshikawa ◽  
Keiko Nishikawa
Keyword(s):  
Multiple Scattering ◽  
Scattering Theory ◽  
Edge Structure ◽  
Multiple Scattering Theory ◽  
X Ray ◽  
Carbon Compounds ◽  
X Ray Absorption
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