Reversible work based quantum transition state theory

A theoretical basis is presented for reversible work evaluation of transition rates within the framework of transition state theory. The method involves computing statistical averages of forces without having to evaluate transition state partition functions or densities, and therefore eliminates the need for a harmonic reference system. The method can be applied to systems of high dimensionality which is particularly important in calculations on quantum systems, where each quantum particle may be represented by several images in a Feynman path integral chain. The relationship between this method and the fixed centroid method of Gillan and centroid density theories is established. The various methods are compared on a model quantum system consisting of an Eckart barrier coupled to a harmonic oscillator.