{
  "annotation_id": "6554ce55-662d-4990-8f59-ca028853b978",
  "date_created": "2026-02-17T05:53:24.230000Z",
  "date_modified": "2026-02-17T05:53:24.230000Z",
  "file_hash": "3bd117cd21a22a4a0836a8c96568a02c9d2dbf2d36e99b2ad60602ae48bd03e3",
  "private": false,
  "record": {
    "abstract": "We demonstrate for the specific case of $C_{3v}$ how the direct-product decomposition scheme for the treatment of symmetry in coupled-cluster (CC) calculations can be extended to non-Abelian point groups. We show that for the two-electron integrals and CC amplitudes a block structure can be obtained by resolving the reducible products of two irreducible representations into their irreducible representations. To deal with the necessary resorts of the ordering of the two-electron integrals and amplitudes, spin-adaptation, and the O(M$^5$) contractions (with M as the number of basis functions) of a CC calculation, we suggest a strategy that uses both the reduced and non-reduced representation of the corresponding quantities and switches back and forth between them. While the reduced representations are the ones used in the O(M$^6$) contractions, the other steps are better carried out in the non-reduced representation. Our pilot implementation of the CC singles and doubles method confirms in test calculations for NH$_3$ and PH$_3$ using different basis sets that significant savings (of more than 20 compared to treatments without symmetry and about 5 compared to treatments using $C_s$ symmetry) are possible and suggest that the exploitation of non-Abelian symmetry would render CC computations on large highly symmetric molecules possible",
    "arxiv_id": "2601.10371",
    "authors": [
      "Malte Hellmann",
      "J\u00fcrgen Gauss"
    ],
    "categories": [
      "physics.chem-ph"
    ],
    "license": "http://creativecommons.org/licenses/by-sa/4.0/",
    "title": "The Direct-Product Decomposition Approach for Symmetry Exploitation in Many-Body Methods in Case of Non-Abelian Point Groups",
    "url": "https://arxiv.org/abs/2601.10371",
    "version": "v1"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b4c1ce98-d767-4835-9fa3-53b0d64f2847",
    "id": "arXiv Dataset",
    "type": "Model",
    "variant": "snapshot-2026-01-17",
    "version": "0.1.0"
  },
  "user_id": 1000002
}