London long-range theory

From the beginning, London s theory was recognized as an expedient, but somewhat arbitrary, device to simplify numerical evaluations and recover quasi-classical interpretations of selected long-range contributions to the total intermolecular interaction in the words of a classic text,25... 

Dalgarno A, Lewis JT (1955) The exact calculation of long-range forces between atoms by perturbation theory. Proc Roy Soc (London) A 233 70-74... 

The energy components are most naturally divided into long-range and short-range terms. The long-range terms may be defined in terms of London s perturbation theory leading to electrostatic, induction and... 

On the other hand, people took a closer look at the symmetrized perturbation theory of Eisenschitz and London, which in principle can give a full potential energy surface (PES), not just the long range of it. 

Extrapolating continuous description of fluid motion to a molecular scale might be conceptually difficult but unavoidable as far as interfacial dynamics is concerned. Long-range intermolec-ular interactions, such as London-van der Waals forces, still operate on a mesoscopic scale where continuous theory is justified, but they should be bounded by an inner cut-off d of atomic dimensions. Thus, distinguishing the first molecular layer from the bulk fluid becomes necessary even in equilibrium theory. In dynamic theory, the transport in the first molecular layer can be described by Eq. (60), whereas the bulk fluid obeys hydrodynamic equations supplemented by the action of intermolecular forces. Equation (61) serves then as the boundary condition at the solid surface. Moreover, at the contact line, where the bulk fluid layer either terminates altogether or gives way to a monomolecular precursor film, the same slip condition defines the slip component of the flow pattern. 

The DLVO theory of stability takes into account the interaction of two kinds of long-range forces which determine the closeness of contact of two particles approaching as a result of Brownian movement. The forces concerned are (i) the London-van der Waals forces of attraction, and (ii) the electrostatic repulsion between electrical double layers. 

The Attractive Dispersion Force. The quantum mechanical theory of the long range attraction was derived by London (1930), and... 

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