{
  "abstract": "Molecular passivation of halide vacancies at lead-halide perovskite surfaces is conventionally attributed to Lewis-base coordination of undercoordinated Pb2+ sites. Density functional theory with spin–orbit coupling on FA0.75MA0.25PbI3 (001) shows this premise is electronically insufficient. Across ten additives, no coordination metric predicts which additives passivate: molybdic acid coordinates at 2.346 Å (−1.14 e) yet leaves the localized Pb(6p) defect trap intact (p = 0.128; +0.29 eV in HSE06), whereas permanganic acid coordinates at 2.156 Å (−1.06 e) and clears it (p ≤ 0.002). The outcomes exhibit discrete bimodal separation (Ashman’s D = 23.11) governed by specific interfacial chemistry: proton transfer forming a hydridic Pb–H bond (H2SO4, p = 0.008) or charge-transfer depopulation into an accessible acceptor manifold (HMnO4). This mechanism rationalizes the observed processing sensitivity of phosphate additives. Screening additives by coordination geometry cannot identify passivants; targeting proton delivery or redox-accessible acceptor levels can.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "name": "Christopher Gaspar Msigwa",
      "orcid": "0009-0008-1362-8629"
    },
    {
      "name": "Muhammad Mateen"
    },
    {
      "name": "Shibing Chu",
      "orcid": "0009-0000-8909-1786"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0bzh4aqes7y3a.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008619/v1",
  "fulltext_url": null,
  "id": "0bzh4aqes7y3a",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008619/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",
      "2208|Perovskite Materials and Applications"
    ]
  ],
  "openalex": "W7212133841",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008619/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-10",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/0bzh4aqes7y3a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15008619",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008619/v2"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Coordination Alone Does Not Passivate Surface Halide-Vacancy States in Lead Halide Perovskites",
  "title_text": "Coordination Alone Does Not Passivate Surface Halide-Vacancy States in Lead Halide Perovskites",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:21Z",
  "url": "https://research.draconitic.com/paper/0bzh4aqes7y3a",
  "venue": "ChemRxiv",
  "versions": []
}