Effective particle diffusivity, D_eff, vs. d_c in a two-phase suspension with N=382, L_p=10, D_M=0.1, D_m=0.01, and pair potential of Eq. (2) with σ=2 and $ϵ=1/6$. Single-particle D_eff data (crosses) are compared with better statistics ensemble averaged data (dots) and the fitting law of Eq. (5) (solid curve), obtained from the corresponding N_m/N vs. d_c curve in Figure 5. Inset: MSD vs. t for different phase topologies.