The criteria is selected so that the relevant geometries are mutually exclusive, i.e. that the summation in Equation 48 reflects a choice of cluster diagrams based on the length of the run of paired charges for a specific set of conformations visited by the path integrals. Finally, we note that there is an asterisk on the chain length N * P ± in the summation over indices s and s . This acknowledges that this summation limit will be decremented by one depending on the cluster diagram, as clusters with > 1 paired contact will have fewer available sets of indices (e.g. N P -1 for B