Distributed polarizabilities

A new method has been developed for describing the response of a molecule to an external electric field. The molecule is divided into regions, and the charge, dipole, quadrupole etc. of each region are modified by the applied potential, electric field, field gradient etc. in the several regions. The method makes it possible to describe more accurately the response to a strongly non-uniform external field (such as the field due to a nearby ion or polar molecule) and is a development of the method of distributed multipole analysis for describing the charge distribution. It differs from previous schemes for assigning polarizabilities to the various regions of a molecule in that it contains explicitly non-local polarizabilities, and in that the lowest-order polarizability is not a dipole-dipole quantity but a charge-charge polarizability.