{
  "abstract": "Extended tight-binding methods are attractive for condensed-phase simulations because they retain an explicit electronic Hamiltonian at a cost far below conventional density functional theory. Their transferability to periodic materials, however, cannot be assessed reliably without a genuinely periodic Hamiltonian, Brillouin-zone sampling, and symmetry-aware crystal calculations. We present a periodic implementation of the second-generation geometry, frequency, and noncovalent interaction parametrization of extended tight binding (GFN2-xTB) in CP2K. The central theoretical ingredient is a multipolar Ewald formulation for the self-consistent shell charges, atomic dipoles, and quadrupoles of GFN2-xTB, together with analytical forces and stress contributions for geometry optimization, cell optimization, and molecular dynamics. For the ranking of ice polymorphs in the DMC-ICE13 data set, periodic GFN2-xTB on a converged 33k-point mesh improves the relative polymorph energies over GFN1-xTB, reducing the mean absolute error from 8.01 to 3.46 kJ mol-1. Because GFN1-xTB and GFN2-xTB differ in several coupled, jointly parametrized terms, this whole-model comparison does not isolate the contribution of multipolar electrostatics. For the LC10 set of cubic covalent and ionic solids, GFN2-xTB yields valid equation-of-state minima for all ten systems, with lattice-constant and cohesive-energy mean absolute errors of 0.062 Å and 1.30 eV per atom, respectively. Periodic GFN2-xTB is evaluated for molecular crystal lattice energies and cell parameters using the X23b data set. Using native Bloch 23-mesh cell optimization with full symmetry reduction, followed by a 33-mesh energy evaluation on the optimized cells, periodic GFN2-xTB gives a mean absolute lattice-energy error of 14.09 kJ mol-1 and a mean absolute relaxed-cell volume error of 5.84% for the full X23b relaxed-cell set. The benchmarks position periodic GFN2-xTB as an efficient electronic structure level for screening, pre-optimization, and large exploratory simulations. This work creates the foundation for periodic anisotropic electrostatics in the extended tight-binding framework and their efficient application in CP2K.",
  "abstract_shown": true,
  "affiliations": [
    "Center for Advanced Systems Understanding (CASUS), Conrad-Schiedt-Straße 20, Görlitz02826, Germany.",
    "Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, Dresden01328, Germany.",
    "Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstraße 4, Bonn53115, Germany.",
    "AI for Science, Microsoft Research, Karl-Liebknecht-Str. 32, Berlin10178, Germany.",
    "Institute of Artificial Intelligence, Technische Universität Dresden, Helmholtzstraße 10, Dresden01069, Germany."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Vahideh Alizadeh"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Johann Pototschnig",
      "orcid": "0000-0002-9982-0556"
    },
    {
      "affs": [
        2
      ],
      "name": "Leopold M Seidler"
    },
    {
      "affs": [
        3
      ],
      "name": "Sebastian Ehlert",
      "orcid": "0000-0001-7809-771X"
    },
    {
      "affs": [
        0,
        1,
        4
      ],
      "name": "Thomas D Kühne",
      "orcid": "0000-0001-5471-2407"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/exgc20v55t7e9.bib",
  "cited_by": 1,
  "doi": "10.1021/acs.jctc.6c01034",
  "fulltext_url": "https://europepmc.org/articles/PMC13602927",
  "id": "exgc20v55t7e9",
  "issns": [
    "1549-9618",
    "1549-9626"
  ],
  "landing_url": "https://europepmc.org/article/MED/42917474",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Advanced Chemical Physics Studies"
    ]
  ],
  "openalex": "W7211961978",
  "pdf_url": "https://europepmc.org/articles/PMC13602927?pdf=render",
  "pmcid": "PMC13602927",
  "pmid": "42917474",
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/exgc20v55t7e9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:02Z",
      "native_id": "MED:42917474",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42917474"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Advanced Chemical Physics Studies",
      "subfield": "amo"
    }
  ],
  "title": "Periodic GFN2-xTB in CP2K: Multipolar Ewald Electrostatics, k-Point Sampling, and Transferability Benchmarks for Solids.",
  "title_text": "Periodic GFN2-xTB in CP2K: Multipolar Ewald Electrostatics, k-Point Sampling, and Transferability Benchmarks for Solids.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:21:02Z",
  "url": "https://research.draconitic.com/paper/exgc20v55t7e9",
  "venue": "Journal of chemical theory and computation",
  "versions": []
}