Application Of Complete Scaling To Simulation Of Critical Properties For Square-Well Dimer

The critical temperature and density of square-well dimer are calculated by grand ensemble Monte Carlo simulation combined with Finite-Size Scaling theory. With the help of finite-size-scaling extrapolation, we obtain the critical temperature is Tc*=1.5495±0.0009, the critical density is pc*=0.1473±0.0007. Vapor-liquid equilibria far from the critical point are explored by grand-canonical hyper-parallel tempering method. We employ the scaling analysis to generate recursively the limiting coexistence curve width and the coexistence diameter near critical point. By fitting the coexistence diameter to scaling relation, we found that the contribution of |t|2βto coexistence diameter for square-well dimmer is larger than that for square-well monomer. This is in consistence with experimental results, i.e. if the ratio of the molecular size to the interaction range is relatively large, then the |t|2βterm dominate the singular behavior of coexistence diameters.