Dielectric response of oxides in the weighted density approximation

Calculations of the static dielectric response ${\epsilon }_{\infty }$ of some simple oxide and mixed transition-metal oxide insulators using the weighted density approximation are reported, including in particular the perovskites ${\mathrm{KNbO}}_3,$ ${\mathrm{KTaO}}_3,$ and ${\mathrm{BaTiO}}_3.$ The results show that even though the weighted density approximation makes only small changes to the local density band gaps, the values of ${\epsilon }_{\infty }$ are consistently lowered, improving agreement with experiment.