The octahedra of anatase and rutile TiO2 both have elongation along the z-axis (apical). Anatase experiences more angular distortion around the equatorial bonds. Why is anatase classified as D2d (meaning the dz^2, dxz and dyz states have an INCREASE in energy), while rutile is D2h (meaning these states have LOWER energy), if both have elongation along the z-axis and should therefore both have reduced repulsion between the central cation and the ligands?
A thought is that the angular distortion of the equatorial ligands somehow stabilizes the d orbitals with only xy components, but I don't know why these components would be more stabilized than those with z components, since the elongation along z should lower the repulsion.© BrainMass Inc. brainmass.com October 10, 2019, 6:26 am ad1c9bdddf
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