Continuum theory of percolation and association

The development of a general theory of clustering is sketched. The primary focus is on the use of the pair connectedness function in problems of correlated clustering and on the Ornstein-Zernike formalism that has been developed to evaluate this function and relate it to observed mesoscopic and macroscopic properties. The treatment here stresses percolation, which has already been found to be directly relevant to complex-matter problems. It goes on to show the way the general theory becomes a theory of chemical association when applied to chemically associating fluids. In the complete-association limit, it becomes a site-site theory of molecular fluids