Dynamical Structure Factor of the Homogeneous Electron Liquid: Its Accurate Shape and the Interpretation of Experiments on Aluminum

Based on a highly self-consistent theory maintaining the exact functional relations between the self-energy and the vertex part, we evaluate the dynamical structure factor S(q,omega) of the electron liquid. We find striking deviations from S(q,omega) in the random-phase approximation (RPA) for /q/>p(F); besides a broad peak in the one-pair excitation region as seen in the RPA, a clear shoulder appears along a steepened slope at low omega due to electron-hole multiple scattering, and a flattened structure follows due to inseparable interference between one-pair and multipair excitations. Our result agrees with experiments on Al on the whole. The remaining discrepancy is ascribed to the band-structure-induced effect.