Equilibrium properties of the lattice fluid with the repulsion between the nearest neighbors on the two-level lattice with nonrectangular geometry

TL;DR

This paper investigates the equilibrium properties of a two-level triangular lattice fluid with nearest-neighbor repulsion, comparing analytical and Monte Carlo results, and finds a first-order phase transition unlike single-level systems.

Contribution

It introduces an analytical diagrammatic approximation for a two-level lattice fluid with repulsion, demonstrating its accuracy against Monte Carlo simulations.

Findings

Analytical approximation matches Monte Carlo data across parameters.

The two-level system exhibits a first-order phase transition.

Repulsion causes distinct phase behavior compared to single-level systems.

Abstract

The equilibrium properties of the lattice fluid with the repulsion between the nearest neighbors on the two-level planar triangular lattice are investigated. The numerical results obtained from the analytical expressions are compared with the Monte Carlo simulation data. It is shown that the previously proposed diagrammatic approximation makes it possible to determine the equilibrium characteristics of the lattice fluid with the repulsion between the nearest neighbors on a two-level lattice with an accuracy comparable to the accuracy of modelling the system using the Monte Carlo method in the entire range of thermodynamic parameters. It was found that, in contrast to a similar one-level system, a lattice fluid with the repulsion between the nearest neighbors undergoes a first-order phase transition.