Polarization effects modification

One of the most efficient ways to treat this problem is to combine the ab initio MO method and the RISM theory, and this has been achieved by a slight modification of the original RISM-SCF method. Effective atomic charges in liquid water are determined such that the electronic structure and the liquid properties become self-consistent, and along the route of convergence the polarization effect can be naturally incorporated. 

The effect of the relative electronegativity of a substituent (R) and/or the delocalization of electrons on a chemical property of a substance. Thus, for a molecule R—R, the polar effect refers to all nonsteric influences and modifications of electrostatic forces operating at the reaction center (R ), relative to some standard molecule, Rq—R. Hence, the term is synonymous with the electronic effect. 

In the present study, we have confirmed the modification of the EGL for the CS from S2 induced by the change of solvent polarity by comparing the EGL in toluene (Tol) and methylcyclohexane (MCH) solution with that in THF. Moreover, we have compared the rate constants ()>p) of the S, state formation by S2 excitation with the decay rate constants (), ) of S2 state in ZP-I series and examined also solvent polarity effects on these rate constants comparing THF with Tol or MCH solutions. 

The majority of interfacial polarization loss processes can be closely approximated by some modification of the Debye description of orientational dipole polarization in homogeneous media (13). The subject of interfacial polarization effects and the dielectric properties of many classes of heterogeneous systems have been reviewed by Van Beek (14). 

More generally, the formation of an itmer hole is accompanied by a polarization effect which produces an increase of the binding energy of about the same order of magnitude for all atomic levels. The polarization takes place rapidly and a modification in the energy of transition between two localized levels could be observed but it should remain weak. 

Substituents on the glycose moiety can have a pronounced effect on the rate of hydrolysis of glycosides. Their effect can be due either to polar effects of the substituents or to resulting modifications of the conformational stability of the molecule. Distinguishing between steric and polar effects of substituents on the sugar moiety is difficult, as has already been pointed out for 2-deoxyglycosides (see pp. 54-57). 

A CS INDO scheme incorporating solvent polarity effects according to Klopman s model is applied to examine geometric modification and solvatochromism of merocyanine dyes exhibiting peculiar behaviours. Qualitatively speaking, the model reproduces quite well the most important effects. The advantages of the CS INDO-solvaton approach with respect to other semiempirical procedures including solvation are discussed. 

Polarization effects, which induce fluctuating dipoles in addition to permanent dipoles on polarizable atoms or molecules, do not produce essential modifications to the energy expressions of pure permanent dipolar systems when written in the context of the Ewald method. Generalization of the Ewald expressions for mixtures of molecules possessing charges, dipoles, quadrupoles and polarizabilities can be found in [49,50] and [51]. 

These results agree well with electrochemical experiments. If dichloromethane solutions of different Msj dusters are contacted to Pt electrodes to which 20 V dc is applied, the duster molecules are degraded as a result of the contact with the electrodes. [109] Polarization effects may be the reason for the decomposition. Electrophoresis is observed without any indication of duster decomposition if the platinum electrodes dip into water layers covering the organic phase in a U-tube. The black, thermodynamically unstable microcrystalline products formed on the Pt surfaces have been identified by X-ray powder diffraction to be novel [(Mi3)J metal modifications. The results from the diffraction experiments indicate a structure consisting of cubic dose packed M13 dusters which are linked via their triangular faces to form a kind of pseudo dose packed structure with M13 dusters as building blocks. 

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