Singular Coexistence-curve Diameters: Experiments and Simulations

Abstract

Precise calculations of the coexistence-curve diameters of a hard-core square-we ll (HCSW) fluid and the restricted primitive model (RPM) electrolyte exhibit mar ked deviations from rectilinear behavior. The HCSW diameter displays a $|t{|}^{1-alpha}$ singularity that sets in sharply for $|t|\equiv |T-T_c|/T_c\lesssim 10^{-3}$; this compares favorably with extensive data for ${SF}_6$, also reflec ted in C${}_2$H${}_6$, N${}_2$, etc. By contrast, the curvature of the RPM diameter va ries slowly over a wide range $|t|\lesssim 0.1$; this behavior mirrors observati ons for liquid alkali metals, specifically Rb and Cs. Amplitudes for the leading singular terms can be estimated numerically but their values cannot be taken li terally.

9 pages and 4 figures

References in corpus (3)

• Yang-Yang Anomalies and Coexistence Diameters: Simulation of Asymmetric Fluids
• Discretization Dependence of Criticality in Model Fluids: a Hard-core Electrolyte
• Fluid Coexistence close to Criticality: Scaling Algorithms for Precise Simulation

Cited by in corpus (7)

• The Nature of Asymmetry in Fluid Criticality
• The critical compressibility factor value: associative fluids and liquid alkali metals
• The nature of the rectilinear diameter singularity
• Is the thermodynamic behavior of the noble fluids consistent with the Principle of Corresponding States?
• The application of the global isomorphism to the study of liquid-vapor equilibrium in two and three dimensional Lenard-Jones fluids
• Universality versus nonuniversality in asymmetric fluid criticality
• Asymmetry of the vapor-liquid coexistence curve: the asymptotic behavior of the "diameter"