{
  "abstract": "Guiding the selection of modern density functional approximations (DFAs) for intermolecular interactions requires diverse benchmark assessments. This work reports the development of a new test set of 86 binary complexes formed between either H 2 O or H 2 S and 31 selected partner species, comprising 15 neutral closed-shell molecules, 7 neutral radicals, 4 closed-shell anions, 2 closed-shell cations, and 3 cation radicals. The radical complexes are susceptible to delocalization error, while the interaction strengths span weak to very strong. Benchmark results are obtained at the coupled cluster singles, doubles and perturbative triples, CCSD(T), level, extrapolated towards the complete basis set limit from augmented triple and quadruple zeta basis calculations. This data is used to assess 17 different density functionals, spanning rungs 2 through 5 of Jacob’s Ladder. In common with other benchmarks, we find that the best functional on each higher rung of Jacob’s Ladder improves over the rung below, consistent with the potential to reduce the delocalization error. Only one functional, the ωB97M(2) double hybrid, achieves an RMS error of less than 1 kcal/mol. The best-performing hybrid is the recently introduced COACH functional, which has an RMS error just below 2 kcal/mol, while the best-performing meta-GGA and GGA have RMS errors above 3 and 4 kcal/mol respectively. These errors are dominated by the complexes that involve radical ions or neutral radicals. While the best-performing functionals are useful, these results indicate that further progress is still needed to address the delocalization error in intermolecular interactions.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry",
    "California",
    "Bay Area Environmental Research Institute",
    "Astrophysics Division",
    "NASA Ames Research Center",
    "Chemical Sciences Division",
    "Lawrence Berkeley National Laboratory"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Rebecca Tomann",
      "orcid": "0009-0006-7021-7872"
    },
    {
      "affs": [
        2,
        3,
        4
      ],
      "name": "Partha P. Bera",
      "orcid": "0000-0003-0843-3209"
    },
    {
      "affs": [
        0,
        1,
        5,
        6
      ],
      "name": "Martin Head-Gordon",
      "orcid": "0000-0002-4309-6669"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/512nhg1wxmwhm.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008618/v1",
  "fulltext_url": null,
  "id": "512nhg1wxmwhm",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008618/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Advanced Chemical Physics Studies"
    ]
  ],
  "openalex": "W7212164127",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008618/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-10",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/512nhg1wxmwhm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15008618",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008618/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "A benchmark dataset of 86 intermolecular interactions of neutrals, ions, radicals and radical ions with water and hydrogen sulfide",
  "title_text": "A benchmark dataset of 86 intermolecular interactions of neutrals, ions, radicals and radical ions with water and hydrogen sulfide",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:19Z",
  "url": "https://research.draconitic.com/paper/512nhg1wxmwhm",
  "venue": "ChemRxiv",
  "versions": []
}