{
  "abstract": "Poorly soluble species can have mean populations below one in small systems such as nanopores. In this regime, the grand-potential minimum, which identifies the most probable particle number, differs from the ensemble-averaged solute loading. We use grand-canonical Wang-Landau sampling (GCWLS) to calculate the density of states $Ω(N_\\mathrm{A}, N_\\mathrm{B})$ for a binary Lennard-Jones mixture of solute B in solvent A, both in bulk and in slit pores. One set of GCWLS simulations gives ensemble averages over a range of chemical potentials, whereas conventional grand-canonical Monte Carlo (GCMC) simulation requires a separate simulation at each state point. Independent GCMC simulations confirm the GCWLS ensemble averages. The solvent number distribution is nearly Gaussian, whereas the dilute solute distribution is skewed and Poisson-like. The most probable solute number therefore lies below the ensemble-averaged loading $\\langle N_\\mathrm{B}\\rangle$ and is zero whenever $\\langle N_\\mathrm{B}\\rangle<1$. Reading the solute loading from the grand-potential minimum underestimates it and can falsely indicate that no solute is present. Defining the oversolubility as $\\mathcal{O}_\\mathrm{B}=x_\\mathrm{B}^{\\mathrm{conf}}/x_\\mathrm{B}^{\\mathrm{bulk}}$, where $x_\\mathrm{B}$ is the solute mole fraction, we find $\\mathcal{O}_\\mathrm{B}\\approx12$ in a pore of 3.5 particle diameters width when both wall interactions are repulsive. Adding wall-solute attraction moderately raises it to $\\approx13$, whereas wall-solvent attraction lowers it to $\\approx3.4$. This comparison shows that the wall-solvent interaction controls most of the enhancement. As the pore widens, $\\mathcal{O}_\\mathrm{B}$ decreases toward unity. In bulk and in nanopores alike, the solubility of poorly soluble species should be obtained from ensemble averages rather than from grand-potential minima.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.16599",
  "author_total": 5,
  "authors": [
    {
      "name": "Russell Kajouri"
    },
    {
      "name": "Adyant Agrawal"
    },
    {
      "name": "Philipp Stärk"
    },
    {
      "name": "Alexander Schlaich"
    },
    {
      "name": "Christian Holm"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ev3m8ghv4e1ed.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.16599",
  "fulltext_url": null,
  "id": "ev3m8ghv4e1ed",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.16599",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.soft"
    ],
    [
      "arxiv",
      "cond-mat.stat-mech"
    ],
    [
      "arxiv",
      "physics.chem-ph"
    ],
    [
      "arxiv",
      "physics.comp-ph"
    ],
    [
      "openalex",
      "2204|Phase Equilibria and Thermodynamics"
    ]
  ],
  "openalex": "W7221777346",
  "pdf_url": "https://arxiv.org/pdf/2610.16599",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ev3m8ghv4e1ed.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.16599",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.16599"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "arxiv:physics.chem-ph",
      "subfield": "physical"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.comp-ph",
      "subfield": "computational"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.soft",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.stat-mech",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Solubility of poorly soluble species in bulk and nanopores from grand-canonical Wang-Landau sampling",
  "title_text": "Solubility of poorly soluble species in bulk and nanopores from grand-canonical Wang-Landau sampling",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/ev3m8ghv4e1ed",
  "venue": "arXiv",
  "versions": []
}