Together with rare-gas fluids, molten alkali metals have always been considered as paradigms of the behavior shown by the so-called “simple liquids”. In the last few years, the appearance of new accurate data for the time dependent properties of these systems has led to renewed interest and to the possibility of more stringent tests for our understanding of the dynamics of the liquid state. The study of the microscopic dynamics of simple liquids such as molten alkalies received renewed interest, particularly, from the point of view to the parallel application of inelastic X-ray and neutron scattering techniques. They have probed deeper investigations of the microscopic mechanism controlling the dynamical behavior like phonon dispersions and related properties extending to wide range of wave vectors and frequencies. The atomistic computational technologies (computational quantum mechanics and molecular simulations) have revolutionalized the field of condensed matter and began to bridge the gap between fundamental materials science and materials engineering.