Dielectric response of oxides in the weighted density approximation

Calculations of the static dielectric response epsilon (infinity) of some s imple oxide and mixed transition-metal oxide insulators using the weighted density approximation are reported, including in particular the perovskites KNbO3, KTaO3, and BaTiO3. The results show that even though the weighted d ensity approximation makes only small changes to the local density band gap s, the values of epsilon (infinity) are consistently lowered, improving agr eement with experiment.