Precise Simulation of Near-Critical Fluid Coexistence

Young C. Kim, Michael E. Fisher, Erik Luijten
2003 Physical Review Letters  
We present a novel method to derive liquid-gas coexisting densities, ρ^±(T), from grand canonical simulations (without knowledge of or criticality class). The minima of Q_L≡< m^2 >_L^2/< m^4>_L in an L×L ×L box with m = ρ - <ρ>_L are used to generate recursively an unbiased universal finite-size scaling function. Monte Carlo data for a hard-core square-well fluid and for the restricted primitive model electrolyte yield ρ^± to ± 1-2 down to 1 part in 10^4-10^3 of (and confirm well Ising
more » ... well Ising character). Pressure mixing in the scaling fields is unequivocally revealed and indicates Yang-Yang ratios R_μ = -0.04_4 and 0.2_6 for the two models, respectively.
doi:10.1103/physrevlett.91.065701 pmid:12935086 fatcat:3wmr3pbmfnf2ddip3i4zhffuwa