Lattice dynamics and dielectric properties ofTiO2anatase: A first-principles study

Lattice vibrations and dielectric properties of the anatase phase of titanium dioxide are investigated from a theoretical perspective. A first-principles pseudopotential band calculation based on density-functional perturbation theory is performed to evaluate normal vibrations, dielectric tensors, and Born effective charges. The present theoretical predictions agree with experimental values overall. Born effective charge tensor elements appear anomalously large, as in the rutile phase, with a larger anisotropy of oxygen. Dielectric permittivity tensors are also discussed in comparison with those of rutile.