Theories of van der Waals Forces Based on Bulk Properties

7 THEORIES OF VAN DER WAALS FORCES BASED ON BULK PROPERTIES 

For the above reasons a theory based entirely on measurable bulk properties rather than molecular parameters is a more powerful way of dealing with the interaction of macroscopic 

In this expression e(/ ) is the dielectric constant —it is a function of frequency —along the imaginary frequency axis / it is measurable as the dissipative part of the spectrum of dielectric constant for any material. The latter is an experimentally determined function of frequency for each of the three components, and the complicated expression in Equation (64) is integrated over all frequencies. 

7b Semiclassical Approaches Based on Bulk Properties Such as Surface Tension 

Because of the complexity of the DLP theory, several semiclassical treatments have been developed to simplify and extend its findings. One such extension is applicable to blocks of nonpolar materials at small separations and is of interest to us because of the possibility it offers for relating surface tension to intermolecular forces. 

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