Chapter 17 - Polarizability of atoms and atomic clusters

Abstract

In this chapter, we present an overview of the theory and computation of polarizability of many-electron systems, in particular atoms and atomic clusters. The direct theoretical approaches in terms of perturbation theory, variation perturbation approach, direct numerical solution of modified Sternheimer-type equations for spherically symmetric situations, direct finite field approach in an ab-initio calculation setup, such as density functional theory, etc., are discussed. For systems such as atomic clusters, which can be considered to be near-spherical, an atom-like description but with different external potential corresponding to jellium model is a reasonably good approximation and is able to predict the occurrence of magic clusters quite well. Some of the explicit calculation-based results are discussed highlighting only the trends and main points learnt.