A binary liquid near its consolute point exhibits critical fluctuations of local composition and a diverging correlation length. The method of choice to calculate critical points in the phase diagram is a finite‐size scaling analysis, based on a sequence of simulations with widely different system sizes. Modern, massively parallel hardware facilitates that instead cubic sub‐systems of one large simulation are used. Here, this alternative is applied to a symmetric binary liquid at critical composition and different routes to the critical temperature are compared: 1) fitting critical divergences of the composition structure factor, 2) scaling of fluctuations in sub‐volumes, and 3) applying the cumulant intersection criterion to sub‐systems. For the last route, two difficulties arise: sub‐volumes are open systems, for which no precise estimate of the critical Binder cumulant Uc is available. Second, the boundaries of the simulation box interfere with the sub‐volumes, which is resolved here by a two‐parameter finite‐size scaling. The implied modification to the data analysis restores the common intersection point, yielding Uc=0.201±0.001, universal for cubic Ising‐like systems with free boundaries. Confluent corrections to scaling, which arise for small sub‐system sizes, are quantified and the data are compatible with the universal correction exponent ω≈0.83.
We have carried out Monte Carlo simulations in Gibbs ensemble for twoand three-dimensional double Yukawa fluid. We have compared liquid-vapour equilibrium curve with that of Lennard-Jones, when parameters occurring in double Yukawa potential are chosen to fit Lennard-Jones potential. The results are in good agreement. The role of repulsive and attractive contributions for the potential on the liquid-vapour coexistence region as well as on critical temperature and critical density has been studied. The critical temperature is found to be more sensitive than the critical density to the variation in repulsive and attractive parts of the potential. Also, the range of the attractive interaction directly influences range of the liquid-vapour coexistence region. It has been found that smaller the values of the attractive parameter, larger is the coexistence region.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.