## Correlation effects in stage velocities

As a result of averaging over local environments around the reagents, the following expressions are obtained for the velocities of monoand bimolecular elementary processes

1, exp( ) ( )z zi i i ij ij ij ii j i jU K S U K S Sθ βε θ −= = − (53.1)

where *ik ik ikδε ε ε= − , and εik* is the interaction parameter between the activated complex (the particle i located at the site f in the transition state) of the elementary process α with the neighbouring particle k at the neighbouring site g, where tij = θ ij/θ i is the conditional probability of finding the particle j near the particle i, calculated in the quasi-chemical approximation. In the derivation of expressions (53.1), it was assumed that the rate constants Ki and Kij weakly depend on the density. In the function Si summation is carried out over all types of neighbouring particles. The functions Si are the factors of the non-ideality function of the reaction system, which reflect the influence of each neighbouring particle on the height of the activation barrier of the reaction:

1 exp( )si ik ikkS t βδε== ∑ – QCA,

– mean-field approximation. In the absence of intermolecular interactions, the multipliers Si = 1 and the formulas go into the reaction rate for the ideal reaction system (48.2).