On nonequilibrium spatial correlations in a model chemical reaction

We study the nonequilibrium spatial correlations of the density fluctuations for a selected reagent as well as the spatial correlations of its energetic states in a stationary state of a model chemical system. In the considered chemical model the reagent of interest appears as a product of a binary process and vanishes as the result of a fast unimolecular decay. Assuming that the lifetime of the reagent is short enough to treat its motion as a ballistic rather than diffusive one we derive analytical formulae for all correlation functions. The results obtained from these formulae agree well with correlations directly measured in molecular dynamics simulations.