Diffusion Theory of Reaction Rates. I. Formulation and Einstein - Smoluchowski Approximation.

The diffusion model of reaction rates is rederived and extended. The derivation is based on a clear physical picture of the molecular events. The origin of the stochastic forces is also clearly treated. Classical mechanics is used throughout. This paper, uses the Einstein-Smoluchowski approximation and, thus, considers, a diffusion model in position space only. The diffusion equations is non-demensionalized and a number of singular perturbation problems are obtained. By using the diffusion model, one can treat a number of problems involving reaction rate theory. A new form of transition state theory is derived. Calculate reaction rate constants, transmission coefficients and the lifetime of the activated complex are calculated.