{
  "abstract": "Molecular hydrogen formation on interstellar dust grains is a key surface process, but the partitioning of recombination energy between the substrate and the nascent molecule remains poorly understood. Here, we use ring-polymer molecular dynamics (RPMD) with a machine-learning force field to investigate energy partitioning during H2 and HD formation on graphene at T=25 K, 50 K and 100 K, focusing on the chemisorbed-H recombination pathway previously identified as the dominant low-temperature channel on bare graphitic surfaces when nuclear quantum effects are included. The desorbing molecule retains approximately 84-87% of the effective released energy, with only weak variation across the three velocity-initialization temperatures under the present sampling protocol. Within the retained molecular energy, rovibrational motion dominates at 25 K, whereas center-of-mass translation becomes increasingly important at 100 K. H2 and HD show similar total energy retention, with modest isotope-dependent differences in their internal partitioning. The effective joint rovibrational distributions show a modest positive association between vibrational and rotational excitation. Purely radiative cascade calculations in the optically thin, collision-free limit yield formation-pumping spectra at all three temperatures. From 25 to 100 K, the rovibrational fraction of the emitted energy decreases from approximately 43% to 28% for H2 and from 41% to 28% for HD, while the strongest lines remain in similar wavelength regions. These results provide an energy-resolved microscopic picture of surface-mediated energy redistribution and formation pumping in H2/HD formation on graphene.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.13843",
  "author_total": 4,
  "authors": [
    {
      "name": "Xiaolong Yang"
    },
    {
      "name": "Lile Wang"
    },
    {
      "name": "Di Li"
    },
    {
      "name": "Shenzhen Xu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/566actkdgs1cy.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.13843",
  "fulltext_url": null,
  "id": "566actkdgs1cy",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.13843",
  "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",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Astrophysics and Star Formation Studies"
    ]
  ],
  "openalex": "W7203625930",
  "pdf_url": "https://arxiv.org/pdf/2608.13843",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/566actkdgs1cy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:36:22Z",
      "native_id": "2608.13843",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.13843"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Energy Partitioning in Dust-catalyzed $\\mathrm{H_2}$ and HD Formation Revealed by Molecular Simulations Considering Nuclear Quantum Effects",
  "title_text": "Energy Partitioning in Dust-catalyzed H_2 and HD Formation Revealed by Molecular Simulations Considering Nuclear Quantum Effects",
  "type": "preprint",
  "updated_at": "2026-11-01T12:20:44Z",
  "url": "https://research.draconitic.com/paper/566actkdgs1cy",
  "venue": "arXiv",
  "versions": []
}