Equation of state of additive hard-disk fluid mixtures: A critical analysis of two recent proposals

TL;DR

This paper critically compares two theoretical equations of state for binary additive hard-disk mixtures, evaluating their accuracy against Monte Carlo data and highlighting the simpler, more compliant proposal by Santos et al.

Contribution

It provides a detailed comparison of two recent equations of state for hard-disk mixtures, emphasizing the advantages of the Santos et al. proposal in simplicity and exact limit compliance.

Findings

Both proposals have similar accuracy with the same input.

The Santos et al. proposal is simpler and more consistent with the exact limit.

Monte Carlo results are used for validation.

Abstract

A detailed analysis of two different theoretical equations of state for a binary mixture of additive hard disks [C. Barrio and J. R. Solana, Phys. Rev. E 63, 011201 (2001); A. Santos, S. B. Yuste and M. Lopez de Haro, Mol. Phys. 96, 1 (1999)], including their comparison with Monte Carlo results, is carried out. It is found that both proposals, which require the equation of state of the single component system as input, lead to comparable accuracy when the same input is used in both, but the one advocated by Santos et al. is simpler and complies with the exact limit in which the small disks are point particles.