Local structure parameters through the fitting of XANES spectra using a multidimensional interpolation: application to the Pd K-edge of Pd-diethynylbiphenyl polymer

• Published in: Journal of physics. Condensed matter 2006-01, Vol.18 (3), p.759-766
• Main Authors: Smolentsev, G, Soldatov, A V, D’Acapito, F, Polzonetti, G, Fratoddi, I
• Format: Article
• Language: English
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/18/3/001

A new method of advanced quantitative analysis of x-ray absorption near edge structure (XANES) is described. The method is based on the fitting of experimental XANES data using multidimensional interpolation of the spectra as a function of the structural parameters and full multiple scattering calculations. Such an approach has several advantages in comparison with schemes that existed before, in particular a very small number of ab initio calculations, significant reduction of required computational time, and the possibility to see immediately the spectrum that corresponds to any set of structural parameters. A first application of the method to determine the parameters of the local geometry of a real system, namely Pd-diethynylbiphenyl, is reported. The procedure of polynomial construction is described in detail for this complex of palladium. The best-fit three-dimensional geometry obtained has the following bond distances: Pd-P 2.36 +/- 0.02 A, Pd-C 2.06 +/- 0.02 A and C-C 1.1 +/- 0.03 A, in agreement with results of previous EXAFS studies.