{
  "abstract": "Automated exploration of reaction networks typically assumes a single potential-energy surface. However, 3d transition-metal catalysis often involves two-state reactivity, where the rate-determining step may occur on a different spin surface. This work presents an open-source extension of AutoMeKin that incorporates spin considerations throughout. The extension features a GFN2-xTB exploration engine with spin-handling capabilities, identification of closely lying spin states, localization of minimum-energy-crossing-points (MECP) at relevant crossings, integration of MECP nodes connected by nonadiabatic edges within the reaction graph, nonadiabatic transition-state-theory rate calculations, and a multireference diagnostic based on ⟨S2⟩ to disable the single-determinant approach where it is not applicable. The extension is tested on three different iron systems. For H2CO and Fe(CO)5, blind path sampling was utilized, whereas targeted transition-state optimization was applied to the more complex cases. Subsequently, MECPs were localized without manual intervention for Fe(CO)5 and Tp-Fe(II)-ethyl, but not for the Fe(I) alkene-isomerization catalyst.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven, Belgium, 3001"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Joshua M. Sims",
      "orcid": "0000-0002-8279-3010"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d0fngj0js8sa3.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010937/v1",
  "fulltext_url": null,
  "id": "d0fngj0js8sa3",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010937/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": "W7211934604",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010937/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/d0fngj0js8sa3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:26Z",
      "native_id": "10.26434/chemrxiv.15010937",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010937/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "Spin-Resolved Reaction-Network Exploration in AutoMeKin with Minimum-Energy-Crossing-Point Localization and an ⟨S2⟩ Single-Reference Check",
  "title_text": "Spin-Resolved Reaction-Network Exploration in AutoMeKin with Minimum-Energy-Crossing-Point Localization and an ⟨S2⟩ Single-Reference Check",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:26Z",
  "url": "https://research.draconitic.com/paper/d0fngj0js8sa3",
  "venue": "ChemRxiv",
  "versions": []
}