Phase behavior of the Lattice Restricted Primitive Model with nearest-neighbor exclusion

TL;DR

This study investigates the phase transitions of a lattice primitive model with nearest-neighbor exclusion, revealing a dominant fluid to charge-ordered solid transition and a metastable liquid-vapor transition within the phase diagram.

Contribution

It provides the first detailed phase diagram of the lattice restricted primitive model with nearest-neighbor exclusion using grand canonical Monte Carlo simulations.

Findings

Charge-ordered solid transition terminates at $ ho^*_{max}=\sqrt2$ and $T^*\approx0.29

First-order transition between charge-ordered and charge-disordered phases at maximum density

Liquid-vapor transition is metastable within the fluid-solid phase envelope

Abstract

The global phase behavior of the lattice restricted primitive model with nearest neighbor exclusion has been studied by grand canonical Monte Carlo simulations. The phase diagram is dominated by a fluid (or charge-disordered solid) to charge-ordered solid transition that terminates at the maximum density, $\rho^*_{max}=\sqrt2$ and reduced temperature $T^*\approx0.29$. At that point, there is a first-order phase transition between two phases of the same density, one charge-ordered and the other charge-disordered. The liquid-vapor transition for the model is metastable, lying entirely within the fluid-solid phase envelope.