Abstract
In order to study the relation between chemical potentials and reactivity we divide the interaction region into physically decisive potential ‘boxes’. Each box is considered to be a small interaction region for a virtual chemical reaction with corresponding virtual transition probability amplitudes. These amplitudes are linked together and superimposed in a ‘state path sum’ which relates local potential properties with exact reaction probabilities. The state path sum is carried out by the supermatrix technique of the statistical theory of chain molecules.