This publication brings together contributions by eminent specialists in the field of the theoretical determination of electric polarizability. The contents of this book cover a wide area of subjects relevant to Chemical Physics, Molecular Physics, Nonlinear Optics and Materials Science. Specific subjects Ab initio and Density functional theory calculations of electric polarizability and hyperpolarizability, intermolecular forces, aromaticity, molecular design, electric properties of solvated molecules, NLO materials, Raman intensisties, polarizability of metal and semiconductor clusters, relativistic effects on electric properties, and more. Common experience had taught us that computational methods originally developed in a given basic science, e.g. physics, can be of paramount importance to other neighbouring sciences, e.g. chemistry, as well as to engineering or technology and, in turn, to society as a whole.