{
  "abstract": "The low-energy sector of the lanthanide $f^n$ shell is to first approximation governed by the interplay of three interactions: Coulomb repulsion, spin-same-orbit coupling and the ligand crystal field potential. To rationalize the energy landscape in different chemical environments, it is desirable to extract the phenomenological crystal field parameters from experimental data; however, in practice, high-dimensional fitting procedures complicate their routine determination. Here, we present a computational extraction procedure based on real tensorial sets and the $U(7)$ canonical chain that, unlike existing operator equivalent methods, takes all $J$ multiplets of the lowest-energy $LS$ term into account, ensuring meaningful results even in the presence of considerable $J$-mixing. Two series of lanthanide compounds, [Ln(III)(C$_8$H$_8$)$_2$]$^-$} and doped Ln(III):Y$_2$O$_3$} (Ln $\\in$ {Ce, Pr, Nd, Sm, Eu}) serve as examples for high- ($D_{8h}$) and low-symmetry ($C_2$) scenarios. Consequences for the generalisation toward actinides are briefly discussed.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.35622",
  "author_total": 2,
  "authors": [
    {
      "name": "Arta A. Safari"
    },
    {
      "name": "Markus Reiher"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/eb3vab7ek2xwg.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.35622",
  "fulltext_url": null,
  "id": "eb3vab7ek2xwg",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.35622",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.chem-ph"
    ],
    [
      "openalex",
      "3104|Rare-earth and actinide compounds"
    ]
  ],
  "openalex": "W7223795204",
  "pdf_url": "https://arxiv.org/pdf/2610.35622",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/eb3vab7ek2xwg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.35622",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.35622"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "arxiv:physics.chem-ph",
      "subfield": "physical"
    }
  ],
  "title": "Lanthanide Crystal Field Theory in the J-Mixing Regime: $f^n$ Configurations",
  "title_text": "Lanthanide Crystal Field Theory in the J-Mixing Regime: f^n Configurations",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/eb3vab7ek2xwg",
  "venue": "arXiv",
  "versions": []
}