Density-functional one-body potential theory of the Fermi surface via the Kohn anomaly

Schönhammer and Gunnarsson have shown that the one-body potential energy V(r) of density-functional theory generates energy bands which do not yield the Fermi surface calculated from the self-energy Σ(k,μ) of the quasiparticles, μ being the chemical potential for a periodic metal crystal. It is stressed here, however, that if this one-body potential approach is used to calculate the phonon dispersion relations, then the correct Fermi surface can be mapped out from the Kohn anomaly.