Charge overlap effects

Kreek H and Meath W J 1969 Charge-overlap effects. Dispersion and induction forces J. Chem. Phys. 50 2289... 

Koide A, Meath W J and Allnatt A R 1981 Second-order charge overlap effects and damping functions for isotropic atomic and molecular interactions Chem. Phys. 58 105... 

The electrostatic, induction, and dispersion terms can be expanded in a convergent series closely related to the multipole expansion, but fully accounting for the charge-overlap effects, the so-called bipolar expansion introduced by Buehler and Hirschfelder199,200. In the local coordinate systems with the origins located at the centers of masses of the monomers A and B, separated by the distance R, and with their x and y axes parallel and aligned along the z axes, the distance between two particles in space can be expressed as follows,... 

Koide A, Proctor TR, Allnatt AR, Meath WJ (1986) Charge overlap effects for first-order molecule-molecule interactions, through high partial wave order, using the N2-N2 interaction as a model. Mol Phys 59 491-507... 

Krauss M, Neumann DB (1979) Charge overlap effects in dispersion energies. J Chem Phys 71 107-112... 

The most important component of the water trimer nonadditive energy is the induction interaction of the second order in V. Its simple mechanism is shown in Fig. 33.3 a permanent multipole moment on monomer A induces multipole moments on monomer B which in turn interact with the permanent multipole moments of monomer C. Higher orders involve interactions between induced moments. The nonadditive induction energy is in general the most important nonadditive component for hydrogen-bonded systems. As already mentioned, it is the only term used—and only in the asymptotic approximation, i.e. neglecting charge-overlap effects—in the polarizable empirical potentials. 

An early computation of a full (i.e. depending on all intermolecular coordinates) PES of two diatomics is the work by Berns and van der Avoird [113] on (N2)2- Their approach is in essence the one sketched above one-cycle SCF to account for first-order exchange and electrostatics (including charge overlap effects) plus multipole-expanded dispersion. The dispersion coefficients were taken from Ref. [114]. 

The Gaussian at P can then be represented by a point charge if charge overlap effects can be ignored. If the basis functions have angular momenta 1, and Ij, then the angular dependence of these is... 

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