{
  "abstract": "We present an extensive molecular dynamics (MD) study of the dynamical properties of a binary hard-sphere fluid over a wide range of packing fractions, $ϕ\\approx 0.357-0.582$. The self-diffusivity, $D$, and shear viscosity, $η$, are computed using an efficient implementation of the Einstein--Helfand method. The finite-size effects in $D$ scale as $1/N^α$, with $α$ increasing from approximately $1/3$ to $3/4$ with increasing $ϕ$, whereas those in $η$ are negligible except for $ϕ\\gtrsim 0.554$, where they scale as $1/N$. The data are then extrapolated to the thermodynamic limit to obtain $D_{\\infty}$ and $η_{\\infty}$. Both coefficients show a super-Arrhenius dependence on $ϕ$ for dense states, accompanied by a breakdown of the Stokes--Einstein relation. Although both $D_{\\infty}(ϕ)$ and $η_{\\infty}(ϕ)$ data are well described by an exponential form, we demonstrate that these fits do not provide reliable estimates of the critical packing fraction, $ϕ_0$, owing to the substantial extrapolation required beyond the accessible equilibrium range. We find the commonly assumed proportionality between $η$ and the structural relaxation time, $τ_α$ , to not hold for this system. For $ϕ\\gtrsim 0.570$, the van Hove self-correlation function $G_s(r, τ)$ exhibits a spatial exponential decay at intermediate times, $τ$, signaling dynamic heterogeneity. The characteristic decay length scales as $λ\\sim τ^ν$, with $ν\\approx 1/3$, in contrast to the conventional square-root scaling. We also investigate temporal heterogeneity through the four-point dynamic susceptibility, $χ_4(τ)$, and its peak time, $τ_4$. These findings provide rigorous benchmark MD data for computational studies of glassy dynamics and establish a reference for testing theoretical models in dense disordered systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.09532",
  "author_total": 2,
  "authors": [
    {
      "name": "Sabry G. Moustafa"
    },
    {
      "name": "Andrew J. Schultz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cxvct5y5k6zts.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.09532",
  "fulltext_url": null,
  "id": "cxvct5y5k6zts",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.09532",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.other"
    ],
    [
      "arxiv",
      "cond-mat.soft"
    ],
    [
      "openalex",
      "2505|Material Dynamics and Properties"
    ]
  ],
  "openalex": "W7212129741",
  "pdf_url": "https://arxiv.org/pdf/2609.09532",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cxvct5y5k6zts.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:12Z",
      "native_id": "2609.09532",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.09532"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.other",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Comprehensive molecular dynamics study of the dynamical properties of a dense binary hard-sphere mixture",
  "title_text": "Comprehensive molecular dynamics study of the dynamical properties of a dense binary hard-sphere mixture",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:12Z",
  "url": "https://research.draconitic.com/paper/cxvct5y5k6zts",
  "venue": "arXiv",
  "versions": []
}