Structure factors for a binary mixture of quantum and classical Fermion liquids

The structure factor S(q) of a liquid metal shows significant differences when measured by neutrons or X rays. Such differences are not apparent in liquids where all the electrons are tightly bound to the nuclei (e.g., Ar). Of particular interest is the presence of a linear dependence in S(q) on the momentum transfer q in the range 0.08 A-1 less than or equal to absolute value q less than or equal to 0.3 A-1. The above results have been postulated to originate in the two fluid nature of a liquid metal (electrons and nuclei). However, microscopic calculations of the electron structure factor have not provided an adequate explanation of this behavior. The authors have now shown that the interaction of the underlying classical liquid of nuclei with the electron fluid, does provide such a linear behavior at small q and also gives additional variation in S(q) at large q