English

Analytical solution for the polydisperse random close packing problem in 2D

Soft Condensed Matter 2025-02-17 v2 Disordered Systems and Neural Networks Materials Science Statistical Mechanics Chemical Physics

Abstract

An analytical theory for the random close packing density, ϕRCP\phi_\textrm{RCP}, of polydisperse hard disks is provided using an equilibrium model of crowding [A. Zaccone, Phys. Rev. Lett. 128, 028002 (2022)] which has been justified on the basis of extensive numerical analysis of the maximally random jammed (MRJ) line in the phase diagram of hard spheres [Anzivino et al., J. Chem. Phys. 158, 044901 (2023)]. The solution relies on the equations of state for the hard disk fluid and provides predictions for ϕRCP\phi_\textrm{RCP} as a function of the ratio, ss, of the standard deviation of the distribution of disk diameters to its mean. For a power-law size distribution with s=0.246s=0.246, the theory yields ϕRCP=0.892\phi_\textrm{RCP} =0.892, which compares well with the most recent numerical estimate ϕRCP=0.905\phi_\textrm{RCP} =0.905 based on the Monte-Carlo swap algorithms [Ghimenti, Berthier, van Wijland, Phys. Rev. Lett. 133, 028202 (2024)].

Keywords

Cite

@article{arxiv.2502.03354,
  title  = {Analytical solution for the polydisperse random close packing problem in 2D},
  author = {Alessio Zaccone},
  journal= {arXiv preprint arXiv:2502.03354},
  year   = {2025}
}
R2 v1 2026-06-28T21:33:43.148Z