Critical behavior of the restricted primitive model revisited

Abstract

Reassessment of the critical temperature and density of the restricted primitive model of an ionic fluid by Monte Carlo simulations performed for system sizes with linear dimension up to $L/\sigma=34$ and sampling of $\sim 10^9$ trial moves leads to $T^*_c=0.04917 \pm 0.00002$ and $\rho_c^* =0.080 \pm 0.005$. Finite size scaling analysis based in the Bruce-Wilding procedure gives critical exponents in agreement with those of the 3d Ising universality class. An analysis similar to that proposed by Orkoulas et al [Phys. Rev. E 63, 051507 (2001)], not relying on an a priori knowledge of the universality class, leads to an unaccurate estimate of $T_c^*$ and to unexpected behavior of the specific heat and value of the critical exponent ratio $\gamma/\nu$.