Density-functional approach to local-field effects in finite systems: Photoabsorption in the rare gases

We present a formalism based on density-functional theory capable of describing polarization-type many-body effects influencing the photoresponse of small electronic systems. The self-consistent field approach we describe incorporates correlations into a local, effective single-particle potential which takes account of the time-dependent fields induced by an external radiation field. In this paper we present calculations of the static polarizabilities, total photoabsorption cross sections, and selected partial photoabsorption cross sections of the rare gases which yield results in good agreement with experiment. A study of the energy and spatial dependence of the local field leads to a clear physical picture of the dielectric properties of these systems.