Maxwell polarization electric moment

In conventional dielectric measurements, one observes the Maxwell polarization or electric moment density P(t) which is induced by an applied electric field E(t), and from this the complex permittivity e as a function of frequency f = u/2ir of the field. For a system of charges e in volume V with displacement z in the field direction z, P is given by... 

In condensed media consisting of molecules, the intermolecular forces such as permanent and induced dipole interactions are generally small compared to intramolecular chemical binding forces. Therefore, the molecular identities and properties are conserved to a certain extent. They nevertheless differ significantly from those of an isolated molecule in the gas phase. Therefore, both in linear and non-linear optics the question arises of how to relate molecular to macroscopic properties. More specifically, how do the individual permanent and induced dipole moments of the molecules translate into the macroscopic polarization of the medium The main problem is to determine the local electric field acting on a molecule in a medium which differs from the average macroscopic field E (Maxwell field) in this medium. 

Macroscopic polarization, 52 Macroscopic polarization field, 53, 54 Macroscopic susceptibility, 33, 35, 53-55 Magnetic dipole moment, 14 Maxwell electric field, 53, 54 Maxwell equation, 53 Maxwell field, 27, 33, 34 Mixed electric magnetic hyper-magnetizabili-ty, 28... 

The strain dependence for electroded pol3rmers that is quadratic in the field consists of two terms one a Maxwell stress due to the attraction of free surface charge on the electrodes, and the other electrostriction, which is a change of dielectric function with strain (158), related to dipole moments induced by the applied electric field. This quadratic term occurs for all materials and does not require a permanent polar moment. A large ambient electrostriction of 4% strain... 

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