Molecular-dynamics-based investigation of scattering path contributions to the EXAFS spectrum: The Cr3¿ aqueous solution case

Extended x-ray absorption fine structure spectra were computed based on molecular-dynamics (MD) struc- tural data of a [ Cr(H2O)6 ]3+ aqueous solution using nonempirical cation-water potentials. An excellent re- production of the experimental spectrum was achieved. A simple estimation of Debye-Waller factors of the multiple-scattering paths is deduced from MD simulations. The influence of the single-scattering path due to the second hydration shell as compared with the multiple-scattering paths within the first hydration shell allows a reasonable determination of the second hydration shell distance R(Cr-OII) within 0.1 Å.