{
  "abstract": "The many-body expansion (MBE) offers a route to high-level wavefunction energies of systems beyond the reach of conventional calculations, but its practical convergence is entangled with basis set superposition error (BSSE), electrostatic embedding, and the scarcity of direct supersystem benchmarks at large size. Here, we show that as the complete-basis-set (CBS) limit is approached, electrostatically embedded three-body MBE, EE-MBE(3), provides accurate absolute and relative HF, RI-MP2, and CCSD(T) energies across water clusters of varying sizes. Critically, the largesystem conclusions are tested against direct same-level supersystem references rather than lowerlevel or extrapolated benchmarks. A distributed canonical RI-MP2 implementation enables a systematic HF/RI-MP2 campaign for 64 and 128 waters with cc-pVXZ and aug-cc-pVXZ basis sets (X = D, T, Q), with three configurations at each cluster size/basis set point. The largest calculation, (H2O)128/aug-cc-pVQZ, contains 22,016 spherical primary basis functions and, to our knowledge, is the largest reported MP2 calculation performed without a local-correlation approximation. At augcc-pVQZ, EE-MBE(3) maintains per-water errors within the 0.09 kcal mol-1 dynamical-accuracy",
  "abstract_shown": true,
  "affiliations": [
    "School of Chemistry",
    "University of New South Wales",
    "School of Computing",
    "Australian National University",
    "Monash Institute of Pharmaceutical Sciences"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Yuhong Jiang"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Jiarui Wang"
    },
    {
      "affs": [
        2,
        3,
        4
      ],
      "name": "Giuseppe M. J. Barca"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Junming Ho",
      "orcid": "0000-0001-9381-924X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2hb568c41ad5h.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009940/v1",
  "fulltext_url": null,
  "id": "2hb568c41ad5h",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009940/v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Advanced Chemical Physics Studies"
    ]
  ],
  "openalex": "W7220686298",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009940/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/2hb568c41ad5h.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15009940",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009940/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "Basis-Set Limit Wavefunction Energies of Massive Water Clusters: Resolution of a Challenge for Many-Body Expansion",
  "title_text": "Basis-Set Limit Wavefunction Energies of Massive Water Clusters: Resolution of a Challenge for Many-Body Expansion",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/2hb568c41ad5h",
  "venue": "ChemRxiv",
  "versions": []
}