Kirkwood-Westheimer theory

Electrostatic correction computed by the Kirkwood-Westheimer theory. 

It should be noted that Kirkwood s formula does not appear in his first publication [240] in the form of Eq. (5-86). Nevertheless, it is this form of Kirkwood s formula which is widely known, representing only one of the terms of a more complex equation given in reference [240] with n= Kirkwood s theory was further developed in papers by Kirkwood, Westheimer, and Tanford [241], Laidler and Landskroener [242], and Hiromi [243]. 

If all of the atoms and charges in the system of interest are explicitly represented and atomic polarization is included, the use of a dielectric constant other than unity would be inappropriate. A variety of models has been used, however, to approximate the dielectric behavior of a macromolecular system where the solvent was not explicitly included. Dielectric constants for the protein interior between 2 and 10 have been employed, as has a distance-dependent dielectric response equal to the distance in angstroms.78 Also, simple forms of the Kirkwood-Westheimer-Tanford model79 have been used to approximate the effect of the aqueous solvent. An approach that may improve our understanding in this area employs linear response theory to evaluate the spatially dependent dielectric response.80 In any such model it is necessary to consider the frequency dependence of the dielectric constant relative to the time scale of the dynamic process under consideration. 

The several continuum models used to evaluate the terms given are, in fact, different versions of the classical reaction field theory introduced by Kirkwood (Kirkwood, 1934 Westheimer and Kirkwood, 1938) and Onsa-ger (1936). The contributions of the first two terms A ajb and A AdBw) to the A a.b value are small and partially compensate each other. Calcula-... 

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