Electronic structure study of liquid germanium based on x-ray-absorption near-edge structure spectroscopy

Based on measured x-ray-absorption near-edge structure spectra of crystalli ne and liquid germanium (c-Ge and l-Ge), multiple-scattering simulation and density-of-states (DOS) self-consistent calculation have been carried out. By using the configurations generated with a reverse Monte Carlo simulatio n, the higher and narrower white line resonance relative to the solid, and the smearing of any other features l-Ge above the edge are reproduced and e xplained, and the metallic character is verified by DOS calculations. The s trong white line for l-Ge is attributed to the high density of states in th e conduction band and partially to the excitonic effect. The DOS of l-Ge is quite high around the Fermi level, as in a metal, while that for c-Ge open s a gap there. Taking the core-hole effect into account, the p-like partial DOS in the vicinity of the absorbing atom shows a DOS "piling up." [S0163- 1829(99)06303-1].