Phase behaviour and the random phase approximation for ultrasoft restricted primitive models
arXiv:1302.5335 · doi:10.1063/1.4791635
Abstract
Phase separation of the ultrasoft restricted primitive model (URPM) with Gaussian charges is re-investigated in the random phase approximation (RPA)---the 'Level A' approximation discussed by Nikoubashman, Hansen and Kahl [J. Chem. Phys. 137, 094905 (2012)]. We find that the RPA predicts a region of low temperature vapour-liquid coexistence, with a critical density much lower than that observed in either simulations or more refined approximations (we also remark that the RPA critical point for a related model with Bessel charges can be solved analytically). This observation suggests that the hierarchy of approximations introduced by Nikoubashman et al. should be analogous to those introduced by Fisher and Levin for the restricted primitive model [Phys. Rev. Lett. 71, 3826 (1993)], which makes the inability of these approximations to capture the observed URPM phase behaviour even more worthy of investigation.
RevTeX 4.1, 4 pages, 2 figures
References in corpus (5)
- Electrostatic correlations: from Plasma to Biology
- Universality class of criticality in the restricted primitive model electrolyte
- Critical behavior of the restricted primitive model revisited
- Ultrasoft primitive model of polyionic solutions: structure, aggregation, and dynamics
- Pair correlation functions and phase separation in a two component point Yukawa fluid
Cited by in corpus (6)
- Electrostatic Correlations and the Polyelectrolyte Self Energy
- Screening properties of four mesoscale smoothed charge models, with application to dissipative particle dynamics
- Screening properties of Gaussian electrolyte models, with application to dissipative particle dynamics
- Mean-field electrostatics beyond the point-charge description
- Liquid-Vapor Transition and Critical Behavior of The Ultrasoft Restricted Primitive Model of Polyelectrolytes : a Monte Carlo Study
- Gas-liquid critical point of the ultrasoft restricted primitive model from analytic theory