Molecular-dynamics study on the influence of nonequilibrium effects on the rate of chemical reaction

A molecular-dynamics model of chemically reacting hard spheres is applied to study the influence of nonequilibrium effects on the rate constant of a thermally activated chemical reaction. It is demonstrated that these effects can be important if the activation energy of a chemical reaction is in the range between 0.5-${\mathit{k}}_{\mathit{B}}$T and 6${\mathit{k}}_{\mathit{B}}$T. The decrease in reaction-rate constant observed in simulations is larger than that predicted by models of a chemical reaction based on Boltzmann or Enskog equations.