Combination of XANES spectroscopy and molecular dynamics to probe the local structure in disordered systems - art. no. 092201

Individual configurations obtained from molecular dynamics have been combin ed with the computation of x-ray absorption near-edge structure (XANES) spe ctra to obtain a theoretical estimation of the spectrum corresponding to a system in a condensed medium lacking long-range order. The influence of the different geometries on the spectrum is studied. The results obtained indi cate that the reproduction of the features of the XANES spectrum requires a good sampling of geometrical arrangements. As a test case, an aqueous solu tion of Cr(H2O)(6)(3+) was selected, since its simulation reproduces well s tructural results. The contribution of the second hydration shell on the sh ape of the spectrum was determined.