Momentum Dependence of the Dynamic Structure Factor of Core Electrons in Metallic Lithium

The dynamic structure factor of the core electrons in metallic lithium, S c ( q , ω), is calculated in a unified way on the basis of both the one-electron and the one-site approximation. The aim is to furnish the first theoretical data which covers the whole range of q and ω. The results are analysed from several angles. It is found that the Compton-to-Raman transition occurs gradually with decreasing q on the interval \(1.5{}qa{}0.2\), a being the orbital radius of core electrons. Experimental studies of S c ( q , ω) in this transition region are expected to provide us with new information on the excitation of core electrons.