title: XANES analysis of spectral properties and structures of arsenate adsorption on TiO(2) surfaces.
abstract: X-ray absorption near-edge structure (XANES) of arsenate adsorption on TiO(2) surfaces was calculated using self-consistent multiple-scattering methods, allowing a structural analysis of experimental spectra. A quantitative analysis of the effect of disorder revealed that the broadening and weakening of the characteristic absorption in experimental XANES was due to the structural disorder of the arsenate-TiO(2) adsorption system. The success with calculating the scattering amplitude of a specific set of paths using the path expansion approach enables the scattering contributions of different coordination shells to the XANES to be sorted out. The results showed that the scattering resonances from high-level shells inherently overlapped onto the first-shell scattering amplitudes, and formed the fine structures in the XANES region. A variation in one oscillatory feature could be due to several structural changes affecting specific single/multiple-scattering amplitudes. Therefore, direct assignments of spectral features with structural elements should be based on adequate theoretical analysis.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
authors.forename: Guangzhi
authors.initials: G
authors.lastname: He
authors.forename: Gang
authors.initials: G
authors.lastname: Pan
authors.forename: Meiyi
authors.initials: M
authors.lastname: Zhang