While the cluster diagrams allow us to connect molecular interactions to model parameters in both the TM and Qin-Larson theory, we do not expect it to be possible to determine these quantities analytically. We resort to using simple Monte Carlo (MC) simulations to obtain values for these parameters, 131 and show that they can provide reasonable estimations of the parameters used in both TM theory and Q-L theory. See schematic in Figure and for the simulation setups to account for the polymer-ion and polymer-polymer interactions respectively. We use a bead-spring MC model to obtain configurations of polymer segments with N sim = 9 monomers at positions r i , which feel a potential that only includes bonding and bending potentials: