Long-wavelength behavior of the exchange-correlation kernel in the Kohn-Sham theory of periodic systems
Long-wavelength behavior of the exchange-correlation kernel in the Kohn-Sham theory of periodic systems
The polarization dependence of the exchange-correlation (xc) energy functional of periodic insulators within Kohn-Sham (KS) density-functional theory requires a ${O(1/q}^{2})$ divergence in the xc kernel for small vectors q. This behavior, exemplified for a one-dimensional model semiconductor, is also observed when an insulator happens to be described as a KS …