Monte Carlo simulation of vapor-liquid equilibrium and critical asymmetry of square-well dimer fluid

The critical behavior of square-well dimer fluid has been investigated using grand canonical ensemble Monte Carlo simulations combined with a histogram reweighting technique, hyper-parallel tempering and finite-size scaling. The critical temperature and density obtained are T(c)*=1.5495±0.0009 and ρ(c)*=0.1473±0.0007, which are 2.5% lower and 5.2% higher than previous results. Coexistence curves both near to and far from the critical point were obtained. The vapor-liquid equilibrium data far from the critical point are consistent with previous results. Simulation results show that the contribution of |t|(1-α) to the coexistence diameter of square-well dimer fluid dominates the critical behavior and the contribution of |t|(2β) is larger than for a hard-core square-well fluid.