{
  "annotation_id": "61487ef4-1385-4883-be67-78deff24be71",
  "date_created": "2026-03-02T18:01:24.039000Z",
  "date_modified": "2026-03-02T18:01:24.039000Z",
  "file_hash": "864ec1d56b5ce3aeabda0ff669d2f5645ac14a9e8ffcf0ff28c4672f7c5a0336",
  "private": false,
  "record": {
    "abstract": "A benchmark ab initio and density functional (DFT) study has been carried out\non the electron affinities of the first- and second-row atoms. The ab initio\nstudy involves basis sets of $spdfgh$ and $spdfghi$ quality, extrapolations to\nthe 1-particle basis set limit, and a combination of the CCSD(T), CCSDT, and\nfull CI electron correlation methods. Scalar relativistic and spin-orbit\ncoupling effects were taken into account. On average, the best ab initio\nresults agree to better than 0.001 eV with the most recent experimental\nresults. Correcting for imperfections in the CCSD(T) method improves the mean\nabsolute error by an order of magnitude, while for accurate results on the\nsecond-row atoms inclusion of relativistic corrections is essential. The latter\nare significantly overestimated at the SCF level; for accurate spin-orbit\nsplitting constants of second-row atoms inclusion of (2s,2p) correlation is\nessential. In the DFT calculations it is found that results for the 1st-row\natoms are very sensitive to the exchange functional, while those for second-row\natoms are rather more sensitive to the correlation functional. While the LYP\ncorrelation functional works best for first-row atoms, its PW91 counterpart\nappears to be preferable for second-row atoms. Among ``pure DFT\u0027\u0027 (nonhybrid)\nfunctionals, G96PW91 (Gill 1996 exchange combined with Perdew-Wang 1991\ncorrelation) puts in the best overall performance. The best results overall are\nobtained with the 1-parameter hybrid modified Perdew-Wang (mPW1) exchange\nfunctionals of Adamo and Barone [J. Chem. Phys. {\\bf 108}, 664 (1998)], with\nmPW1LYP yielding the best results for first-row, and mPW1PW91 for second-row\natoms. Indications exist that a hybrid of the type $a$ mPW1LYP + $(1-a)$\nmPW1PW91 yields better results than either of the constituent functionals.",
    "arxiv_id": "physics/9902026",
    "authors": [
      "Glenisson de Oliveira",
      "Jan M. L. Martin",
      "Frank de Proft",
      "Paul Geerlings"
    ],
    "categories": [
      "physics.chem-ph",
      "physics.atom-ph",
      "physics.comp-ph"
    ],
    "doi": "10.1103/PhysRevA.60.1034",
    "journal_ref": "Physical Review A 60, 1034-1045 (1999)",
    "title": "Electron affinities of the first- and second- row atoms: benchmark ab   initio and density functional calculations",
    "url": "https://arxiv.org/abs/physics/9902026"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8d29284c-410f-4e6b-bd26-ad98e70e6709",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}