Electric polarizability tensor

Table 10 Number (N) of non-zero and mutually independent (/) elements of the electric polarizability tensors a, p, and y...

In atomic and simple molecular liquids, the Kerr effect, electric saturation, etc., are caused not only by non-linearities directly induced in the atoms and molecules by the external electric field (the Voigt effect), but are primarily due to Yvon-Kirkwood fluctuational-statistical processes. One should keep in mind, however, that the intrinsic electric polarizability of non-dipolar molecules is subject to modification by at least three factors (i) the effect of translational fluctuations, (//) intermolecular attractive or repulsive forces, and (in) non-linearities induced by the tenq>oraIly and spatially fluctuating electric fields of neighbouring molecules. Thus, the Yvonr-Kirkwood process discussed in Section 4 leads, in dipolar approximation, to the following variation of the electric polarizability tensor of a molecule immersed in a statistically noit-uniform medium ... 

Our simulation has shown that polyions are on average completely shielded electrostatically by counterions even in salt-free solutions. Two kinds of counterions, condensed and those forming a diffuse ion atmosphere, are distinguished not only by their spatial distributions but also by their fluctuation or polarization behaviors. The contribution from condensed counterions to the radial components of the electrical polarizability tensor is very small, as has often been postulated in various theories previously. But that from the diffuse ion cloud is very large and cannot be neglected in the calculation of the anisotropy. We have succeeded in the computational reproduction of one of the characteristic properties of polyelectrolytes in salt-... 

Molecules may similarly be oriented using external electric fields For a uniaxial molecule with diagonalized electric polarizability tensor components a, the polarizability contribution to the electro-... 

As an example, let us discuss the case of the electric moment (15) induced by a static external electric field having a uniform gradient. The equation that describes the change of the mixed third-rank electric polarizability tensor (19) with respect to a change to the origin of the coordinate system is... 

The Stark effect of a rotational level is determined by the permanent electric dipole moment ju, the electric polarizability tensor a of the molecule and the applied electric field E. The Hamiltonian of these interactions can be given as ... 

In O Eq. 11.185, a is the (frequency-dependent) electric polarizability tensor, and i, the magne-tizabUity tensor. The two contributions to the molar Cotton-Mouton constant in O Eq. 11.183 are, therefore, a temperature-independent term related to the hypermagnetizabUity and a temperature-dependent molecular orientational part - the Langevin term. ... 

In addition to the Stark effect produced by the permanent dipole moment, small electric dipole moments are induced by the electric field, and this effect is characterized by the electric-polarizability tensor a. This is important only with very large electric fields and will not be discussed further. 

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