Nonlocal density approximation to exchange and correlation: Ground state properties of solid copper and vanadium

Fermi surface parameters and x-ray scattering form factors of Cu and V are calculated using an approximation for the exchange-correlation potential, which is nonlocal in the electronic density. For Cu the results are very close to recent experimental data, especially the neck radius of the Fermi surface is reproduced almost exactly. For V, where previous calculations in LDA so far gave much too large Fermi surface ellipses, non-local effects in the long range part of the xc-potential decrease the size of these ellipses so drastically, that they now become too small. The residual discrepancy may be attributed to a local approximation of the short range part of the xc-potential in the present calculation.