We are using a shorthand here to simplify this expression. The products over α and γ are over the species (P +, P -, +, and -) that interact via electrostatics. The product over indices i and j represents products over all particles (or monomers) in each species, of which there are n α N α particles for each. N α is the degree of polymerization of α, with N α=± = 1 for nonpolymeric species. There are integrals over the positions of salt or monomer particles, with the path integral denoting the integration over all monomer positions for a given chain. 116