Coordination octahedron distortion effect on x-ray absorption fine structures of titanium in the rutile titanium dioxide

We have computed the x-ray absorption spectrum for the Ti K-edge in rutile titanium dioxide (TiO2) in the frame of the multiple scattering approach, v arying the atom positions within the coordination sphere. This allowed us t o understand the origin of the absorption structure variation. The analysis has been achieved by making distortions of the axial and equatorial Ti-O d istances or of the O-eq-(T) over cap i-O-eq equatorial angle along the c ax is. Computations are performed using FEFF (version 6) code for TiO2 with Di rac-Hara and Hedin-Lundqvist exchange potentials. From the results, we can better understand why the amplitude of one or several structures is modifie d referring to TiO2, when a variation of the local geometry occurs.