Generalized viscosity, pair potential, and memory functions from S(q,ω) measurements for liquid metals

The aim of the present work is to perform an in-depth analysis of neutron scattering data on liquid metals and to extend previous types of comparisons between experimental scattering functions and various model theories. The kinematic viscosity {ν}(q) for some liquid metals---liquid lead at 623 and 1173 K, liquid bismuth at 578 K, and liquid rubidium at 315 K---is derived, based on the dynamical scattering functions S(q,{ω}), and compared to molecular dynamics data for hard spheres. The general behavior of the {ν}(q) curve is traced. With use of an analytical form of pair potential with several free parameters, a form of V(r) for liquid lead at 623 K is derived. Finally, the short-time interaction part of the experimental memory function Φₗ(q,t) for the longitudinal current correlation function is directly compared to the corresponding result calculated from kinetic theory in the mode-coupling version. This comparison is based upon the derived form of the interatomic potential for Pb at 623 K and upon other known potential data for Rb at 315 K.