SELF-CONSISTENT WEIGHTED DENSITY APPROXIMATION FOR SIMPLE METAL-SURFACES

The main properties of a metal surface in the jellium model are analyzed within the non-local "self-consistent weighted-density approximation" (SC-WDA) for the functional of the exchange and correlation energy. For general surface properties (surface energy, work function, etc.) we get similar results to the local-density (LDA) ones. We have also used a modification of the SC-WDA by using an interpolation scheme by Serena et al. for the potential out of the surface; in this way we get the correct limit for the image potential. Our results show that the position of the image plane is pulled out from the surface when compared with the LDA calculation, whereas for other calculations the position is closer to the surface. In any case, our results are not very sensitive to whether we use the interpolation procedure or not.