Conduction band electronic structure of metallic beryllium

We have measured the bulk energy-momentum-resolved density of the conductio n band of metallic beryllium by means of electron momentum spectroscopy. Fr om the data we have determined the band dispersion, occupied bandwidth, ele ctron momentum density and density of states. The experimental results are compared with theoretical band-structure calculations performed within the full-potential linear muffin-tin orbital (FP-LMTO) approximation. There is good agreement between experiment and theory for the shape and intensity of the conduction band provided multiple-scattering and hole lifetime effects are included. The measured occupied bandwidth is 11.15 +/- 0.15 eV, which is larger than that predicted by our LMTO calculation, but agrees well with previous experimental and theoretical data. The experiment also reveals th at the band dispersion is narrower in momentum compared to theory, the diff erence reaching as much as 0.15 au near the free-electron]Fermi momentum.