Dielectric response of oxides in the weighted density approximation

Calculations of the static dielectric response ε_∞ of some simple 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 density approximation makes only small changes to the local density band gaps, the values of ε_∞ are consistently lowered, improving agreement with experiment.