{
  "abstract": "Iterating the Dyson equation with the static part of the self-energy leads to a concise and possibly improved expression of the one-body reduced density matrix from any self-energy approximation. Here we apply the procedure to Hedin's $GW$ approximation. The non-iterated $GW$ based density matrix was already known to yield accurate density matrices for molecular systems. We show that the Dyson-equation-based procedure is equivalent to the so-called variational Z-vector approach applied to the Random-Phase approximation energy functional, but only in the case of a Hartree-Fock mean-field starting point. When a generalized Kohn-Sham scheme is employed instead, the two approaches differ. By comparing the density matrix for a benchmark set of 34 small molecules to coupled-cluster reference values, we conclude that the iterated Dyson equation indeed produces improved density matrices for molecular systems. Interestingly, we observe that the excitation rank of the reference coupled-cluster matters much and that the inclusion of triple excitations (CCSDT) quantitatively changes the conclusions of the benchmark as compared to single and double excitations coupled-cluster (CCSD).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2607.15695",
  "author_total": 4,
  "authors": [
    {
      "name": "Fabien Bruneval"
    },
    {
      "name": "Erik Verzijl"
    },
    {
      "name": "Arno Förster"
    },
    {
      "name": "Mauricio Rodriguez-Mayorga"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a1yq79g3m4d00.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.15695",
  "fulltext_url": null,
  "id": "a1yq79g3m4d00",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.15695",
  "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",
      "physics.chem-ph"
    ],
    [
      "arxiv",
      "physics.comp-ph"
    ],
    [
      "openalex",
      "3107|Advanced Chemical Physics Studies"
    ]
  ],
  "openalex": "W7169767812",
  "pdf_url": "https://arxiv.org/pdf/2607.15695",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a1yq79g3m4d00.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2607.15695",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.15695"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "arxiv:physics.chem-ph",
      "subfield": "physical"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.comp-ph",
      "subfield": "computational"
    }
  ],
  "title": "$GW$ reduced density matrix from iterated linearized Dyson equation",
  "title_text": "GW reduced density matrix from iterated linearized Dyson equation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/a1yq79g3m4d00",
  "venue": "arXiv",
  "versions": []
}