Exchange and correlation potential in silicon

A simple model of non-local exchange and correlation is proposed for the valence bands of silicon which could be used to include non-locality in a pseudopotential calculation. The model was fitted to a calculation of the exchange and correlation energy which went beyond previous calculations in using a dynamic dielectric function. It was found that the Gamma point is sensitive to whether a dynamic interaction is used or not. It is hoped to extend the model to conduction bands.