Hydrodynamic approach to time-dependent density functional theory; Response properties of metal clusters

Performing electronic structure calculations for large systems, such as nanoparticles or metal clusters, via orbital based Hartree–Fock or Kohn–Sham theories is computationally demanding. To study such systems, therefore, we have taken recourse to the hydrodynamic approach to time-dependent density-functional theory. In this paper we develop a variation-perturbation method within this theory in terms of the particle and current densities of a system. We then apply this to study the linear and nonlinear response properties of alkali metal clusters within the spherical jellium background model.