Polarizabilities of atoms and molecules, new insights into an old subject

The importance of electric polarizabilities is discussed in detail. Emphasi s is given not only to the dipole-dipole polarizability <(alpha)over cap>, but also to the dipole-quadrupole, dipole-octopole and quadrupole-quadrupol e polarizabilities (A) over cap, (E) over cap, and (C) over cap, respective ly, as examples for the higher-order polarizabilities. In the case of the n onlinear polarizabilities we concentrate on the second hyperpolarizability <(gamma)over cap> and the quadrupole-dipole-dipole polarizability (B) over cap. New experimental techniques such as the asymmetric white-light interfe rometry, atomic-beam interferometry, electric field deflection techniques, and collision-induced spectroscopy are discussed. Recent experimental and t heoretical results are presented for the frequency, density, and temperatur e dependence of the polarizabilities. Special emphasis is given to new resu lts concerning the frequency dependences of the mean dipole-polarizability of molecular iodine and of the polarizability anisotropy of carbon dioxide in the gas phase. An outlook is given for future work devoted to polarizabi lities. (C) 2000 Elsevier Science Ltd. All rights reserved.