{
  "abstract": "Linear chains of hypervalently bonded chalcogen atoms are attractive building blocks for topological materials, but they almost always dimerize or modulate, and the few known examples are confined to actinide compounds. Here we show that Se, mixed Se/Te, and Te chains that are equidistant in their extended crystal structures are stabilized in a new Ibam structure type, Ba 2 Cu 2−x Fe 1+x Se 5−y Te y (y = 0 to 3.2), by combining a low reaction temperature (750 °C), aliovalent Cu/Fe mixing, and a geometric matching between the chains and ribbons of edge-sharing (Cu/Fe)Se 4 tetrahedra. Single-crystal X-ray diffraction at 100 and 300 K shows no superstructure for any composition, whereas the displacement parameters reveal static displacements of the Se atoms along the chain (0.17 Å rms) that decrease with Te substitution and vanish for the Te chain. The ribbons order antiferromagnetically at 132–151 K without a net moment, and the Curie constants show that the Fe(II)/Fe(III) ratio adjusts to place a charge of −0.8 to −1.3 on each chain Se atom, bracketing the value of −1 that is optimal for hypervalent bonding. Electronic structure calculations show steep chain bands and a chain bond index that is independent of the Cu/Fe ratio, and a magnetic symmetry analysis shows that the chain-band crossings persist as fourfold Dirac points in the antiferromagnetic state, about 0.4 eV below the Fermi level. Aliovalent cation mixing thus provides a chemical handle on the electron count of hypervalent chalcogen chains.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry and Biochemistry",
    "Baylor University",
    "Materials Science Center",
    "National Laboratory of the Rockies",
    "Department of Chemistry",
    "North Carolina State University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Subhendu Jana"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "E.A. Chirantha Edirisinghe"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Ian Leahy"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Milena Jovanovic"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Rebecca W. Smaha"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Paul A. Maggard",
      "orcid": "0000-0002-3909-1590"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/497ac2bhrm0py.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010438/v1",
  "fulltext_url": null,
  "id": "497ac2bhrm0py",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010438/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|Topological Materials and Phenomena"
    ]
  ],
  "openalex": "W7221765097",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010438/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/497ac2bhrm0py.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010438",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010438/v1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Topological Materials and Phenomena",
      "subfield": "amo"
    }
  ],
  "title": "Electron Counting by Design: Antiferromagnetic Ribbons Double as Charge Reservoirs to Stabilize Hypervalent Selenium and Tellurium Chains",
  "title_text": "Electron Counting by Design: Antiferromagnetic Ribbons Double as Charge Reservoirs to Stabilize Hypervalent Selenium and Tellurium Chains",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/497ac2bhrm0py",
  "venue": "ChemRxiv",
  "versions": []
}