Effective screening length and quasiuniversality for the restricted primitivemodel of an electrolyte solution

摘要

Monte Carlo simulations for the restricted primitive model of an electrolyte solution above thecritical temperature are performed at a wide range of concentrations and temperatures.Thermodynamic properties such as internal energy, osmotic coefficient, activity coefficient, as wellas spatial correlation functions are determined. These observables are used to investigate whetherquasiuniversality in terms of an effective screening length exists, similar to, the role played by theeffective electron mass in solid-state physics. To that end, an effective screening length is extractedfrom the asymptotic behavior of the Fourier-transformed charge-correlation function and pluggedinto the Debye-Huckel limiting expressions for various thermodynamic properties. Comparisonwith numerical results is favorable, suggesting that correlation and other effects not captured on theDebye-Huckel limiting level can be successfully incorporated by a single effective parameter whilekeeping the functional form of Debye–Huckel expressions. We also compare different methods todetermine mean ionic activity coefficient in molecular simulations and check the internalconsistency of the numerical data.