Electronic structure and momentum density distribution of titanium dioxide

LCAO calculations have been performed for the electronic and structural properties of the rutile TiO2 under the periodic HF and DFT schemes. The methods have been applied to study Compton profiles and the structure factors. The experimental Compton profile based on Am-241 Compton spectrometer for polycrystalline TiO2 has been compared with the calculations. The calculated Compton profile from HF-LCAO has been found to be in good agreement with the measurement compared to the ionic model and DFT-LCAO method. The published experimental X-ray structure factors support the FLAPW method more than the periodic HF-LCAO method. Signatures of charge transfer on compound formation are observed. Partial ionic as well as covalent character of bonding is observed on the basis of structure factor as well as momentum density analysis. The present work enables to examine the DFT and HF approaches in terms of structure factor and the Compton profile studies. (c) 2007 Elsevier B.V All rights reserved.