An extension of the Marcus equation: the Marcus potential energy function.

An analytic potential function consistent with the Marcus equation for activation energy is formulated and used to reveal new insights into the activation process in chemical reactions. As for the Marcus equation, the new potential function depends only on two parameters, the reaction energy and the activation energy (or the so-called Marcus intrinsic activation energy). Combination of the Marcus potential with the reaction force analysis provides two-parameter analytic expressions for the reaction force, reaction force constant, and reaction works. Moreover, since the parameters necessary to define the Marcus potential energy function can be obtained experimentally, the present model may produce experimental analytic potentials allowing for new and interesting applications, thus emerging as a powerful tool to characterize activation processes in chemical reactions.