Evidence of nonlinearity of chemical rate constant expression from MD simulation

Abstract. An elementary reaction is studied from MD where it was found that the rate constant is not constant over the concentration profile of the reactants and products, and this variation is expressed in terms of the reactivity coefficients, and the ratio of these terms for forward and backward steps was found equal to the activity coefficient ratio for the product and reactant species. This result implies that the form for the rate expression is not complete in the way it has been used in nearly all major treatments, and a more complete theory is required to deal with even elementary reactions, meaning those reactions that corresponds to the molecularity of the single (elementary) step.