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A wavelet analysis for the X-ray absorption spectra of molecules.

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Publication date 2013
Author Penfold T J, Tavernelli I, Milne C J, Reinhard M, Nahhas A El, Abela R, Rothlisberger U, Chergui M,
Project Computational simulations for ultrafast X-ray spectroscopy and diffraction of chemical and biological systems
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Original article (peer-reviewed)

Journal The Journal of chemical physics
Volume (Issue) 138(1)
Page(s) 014104 - 014104
Title of proceedings The Journal of chemical physics
DOI 10.1063/1.4772766


We present a Wavelet transform analysis for the X-ray absorption spectra of molecules. In contrast to the traditionally used Fourier transform approach, this analysis yields a 2D correlation plot in both R- and k-space. As a consequence, it is possible to distinguish between different scattering pathways at the same distance from the absorbing atom and between the contributions of single and multiple scattering events, making an unambiguous assignment of the fine structure oscillations for complex systems possible. We apply this to two previously studied transition metal complexes, namely iron hexacyanide in both its ferric and ferrous form, and a rhenium diimine complex, [ReX(CO)(3)(bpy)], where X = Br, Cl, or ethyl pyridine (Etpy). Our results demonstrate the potential advantages of using this approach and they highlight the importance of multiple scattering, and specifically the focusing phenomenon to the extended X-ray absorption fine structure (EXAFS) spectra of these complexes. We also shed light on the low sensitivity of the EXAFS spectrum to the Re-X scattering pathway.