APPLICATION OF MULTIPLE-SCATTERING CALCULATION TO THE STUDY OF LOCAL GEOMETRY IN SILICATE-GLASSES OF GEOLOGICAL INTEREST

Multiple scattering calculations have been used to study the effects o f coordination number, geometry, symmetry and polyhedral distortion on the titanium XANES spectra. The calculations show the influence of ea ch parameter to the Ti K-edge XANES spectra and in particular how the polyhedral distortion affects the spectrum. The small clusters used fo r the calculations represent some possible geometries of titanium atom s in silicate glasses, where Ti is coordinated by oxygen and is found to be in different geometrical environments, mainly as a function of g lass composition.