{
  "abstract": "The size-dependent adsorption of molecular nitrogen on small silver clusters, Ag n N 2 (n = 1–6), is investigated by density functional theory, and an adsorption energy of −0.44 eV, two-to seven fold stronger than for any neighboring cluster size, is identified for n = 3, accompanied by the only appreciable N–N bond elongation in the series. Complete active space self-consistent field calculations reveal that this coincides with static correlation that grows substantially along the N–N stretching coordinate, a correlation index rising from 1.14 to 4.15 between equilibrium and 2.40 Å. Over the same range, the Lee–Taylor T 1 diagnostic from coupled-cluster theory with single, double, and perturbative triple excitations is found to plateau between 0.03 and 0.05, and, for a second cluster, to fall from a maximum of 0.042 to 0.030 as the bond is stretched further. This diagnostic blind spot is confirmed, in a markedly amplified form, for the dissociation of free dinitrogen, where explicit wavefunction-stability analysis establishes that the coupled-cluster reference becomes variationally unstable precisely where the diagnostic offers no warning. Motivated by this finding, a sixteen-qubit unitary coupled-cluster variational quantum eigensolver calculation, comprising approximately 5,700 Pauli terms, is benchmarked against the multireference reference across the identical coordinate, reproducing the reference energy to within 0.29–0.39 mE h at equilibrium and 6.0 mEh at the most strongly correlated geometry examined. These results establish a concrete, cross-validated case study of a practically consequential coupled-cluster diagnostic limitation, together with a physically motivated demonstration that a variational quantum algorithm reproduces the correct multireference physics in a regime where the conventional single-reference benchmark cannot be trusted.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "name": "Mohsen Doust Mohammadi",
      "orcid": "0000-0003-2449-2962"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bkhqx7q790aje.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008096/v1",
  "fulltext_url": null,
  "id": "bkhqx7q790aje",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008096/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": "W7204768527",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008096/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/bkhqx7q790aje.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008096",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008096/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "Static correlation, a coupled-cluster diagnostic blind spot, and its quantum-computing resolution in silver–dinitrogen clusters",
  "title_text": "Static correlation, a coupled-cluster diagnostic blind spot, and its quantum-computing resolution in silver–dinitrogen clusters",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/bkhqx7q790aje",
  "venue": "ChemRxiv",
  "versions": []
}