{
  "abstract": "The chemical bond is among the oldest ideas in chemistry and still among the least settled: chemists continue to disagree about what a bond is. We argue that the recurring controversies (ionic versus covalent, dative versus shared-electron, hypervalent versus metavalent, whether metal–metal contacts are genuinely collective) are not disputes about the physics but about an unstated reference against which a bond is declared. Removing the reference forces a change of viewpoint: an atom in a molecule is not a fixed piece of electron density but an open quantum system, a mixed state that is a probabilistic superposition over how many electrons it owns. From this vantage the electronnumber fluctuations that the theory of electron distribution functions has long measured acquire a sharp meaning: they are the quantum correlation, the entanglement, shared between the atoms of a molecule. Measured directly between the Bader basins chemists already draw, this entanglement yields a single, reference-free bond order in which the electron pair of Lewis, the resonance of Pauling and the delocalization of Mulliken reappear not as assumptions but as consequences. We outline the open-systems formulation of Quantum Chemical Topology that makes the picture exact, and sketch how the same quantity is the natural readout of molecular quantum computation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "D. J. L. Rodrigues"
    },
    {
      "name": "E. Francisco"
    },
    {
      "name": "A. Martín Pendás"
    },
    {
      "name": "Ángel Martín Pendás",
      "orcid": "0000-0002-4471-4000"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7dsdatgya99aa.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010244/v1",
  "fulltext_url": null,
  "id": "7dsdatgya99aa",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010244/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": "W7221552404",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010244/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-11",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/7dsdatgya99aa.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15010244",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010244/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "The Chemical Bond in the Age of Quantum Information: Atoms in Molecules as Entangled Open Systems",
  "title_text": "The Chemical Bond in the Age of Quantum Information: Atoms in Molecules as Entangled Open Systems",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/7dsdatgya99aa",
  "venue": "ChemRxiv",
  "versions": []
}