Near neighbour correlations correlation

However, as near-neighbour correlations are neglected completely in the Bragg-Williams approximation, the theory is unable to account for the specific heat and other anomalies in the isotropic phase. An attempt has been made to extend the theory by using the quasi-chemical or first... 

CJearly near-neighbour correlations have to be allowed for in the molecular statistical approach to give a better description of the pretransition effects. A step in this direction was taken in which... 

Near-neighbour correlations Bethe s method 2.6.1 The Krieger-Jantes approximation... 

In this expression T20 is determined by the way in which the shape of one molecule distorts the radial distribution function away from spherical symmetry whilst T22 is determined by mutual orientational correlation between molecules. The distribution function of model diatomics obtained in computer simulations showed that the T22 effects were much smaller than the orientation-position effects given by T2q The effect of the T2q terms on Yeff sn be simply interpreted for a cylindrical molecule the closest neighbours must lie around its waist. If the cylinder is aligned with an external field (ie if the field is parallel to the molecular z axis) then the dipole induced by the field in the near neighbours will tend to reduce the net field along the cylinder axis as the dipole induced in the cylinder by a given external field is thereby reduced the effect is to reduce Ugz Conversely if the cylinder is perpendicular to the field (ie parallel to x) the dipole... 

When the concentrations of reagents have comparable values, it is necessary to pay attention to the correlation effect in the decay of different donors, i.e. to consider the fact that the spatial distribution of acceptors near the chosen donor can change as a result of the decay of the acceptors in the reactions with other donors neighbouring the chosen one. The rigorous derivation of kinetic equations with the consideration of such a correlation is, as far as we know, unavailable. The approximate description of the kinetics of a biomolecular electron tunneling reaction at n(t) = N t) can be given in terms of the pair density method with the help of eqn. (19) in which, however, N is not a constant quantity but depends on time in the same way as n(t), i.e. 

As discussed in Section 1.2.1, for such systems near the percolation threshold Pc the nearest-neighbour occupied bonds (or sites) form a statistically defined super-lattice , made of tortuous link-bonds (of chemical length Lc) crossing at nodes separated by an average distance the percolation correlation length (see Fig. 1.3 of Chapter 1). The external stress... 

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