{
  "annotation_id": "4af58ddf-a602-4d55-bcbb-5135ba39164f",
  "date_created": "2026-03-02T18:00:42.402000Z",
  "date_modified": "2026-03-02T18:00:42.402000Z",
  "file_hash": "58fe6921ce8eb2cefad328453dc8f9b3853c3cbf25d3cb9865722dd3547adc62",
  "private": false,
  "record": {
    "abstract": "This work presents a method for the ab initio calculation of isotope shift in\natoms and ions with one valence electron above closed shells. As a zero\napproximation we use relativistic Hartree-Fock and then calculate correlation\ncorrections. The main motivation for developing the method comes from the need\nto analyse whether different isotope abundances in early universe can\ncontribute to the observed anomalies in quasar absorption spectra. The current\nbest explanation for these anomalies is the assumption that the fine structure\nconstant, alpha, was smaller at early epoch. We test the isotope shift method\nby comparing the calculated and experimental isotope shift for the alkali and\nalkali-like atoms Na, MgII, K, CaII and BaII. The agreement is found to be\ngood. We then calculate the isotope shift for some astronomically relevant\ntransitions in SiII and SiIV, MgII, ZnII and GeII.",
    "arxiv_id": "physics/0305068",
    "authors": [
      "J. C. Berengut",
      "V. A. Dzuba",
      "V. V. Flambaum"
    ],
    "categories": [
      "physics.atom-ph",
      "astro-ph"
    ],
    "doi": "10.1103/PhysRevA.68.022502",
    "journal_ref": "Phys.Rev.A68:022502,2003",
    "title": "Isotope shift calculations for atoms with one valence electron",
    "url": "https://arxiv.org/abs/physics/0305068"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8e711e34-25ee-417c-be37-1f115f4f8fb3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}