{
  "abstract": "Mobile interstitial atoms redistribute while defects migrate, complicating prediction of defect kinetics and leading to contradictory reports of acceleration and retardation. We formulate defect activation in a grand-canonical ensemble at fixed interstitial chemical potential and define a pathway free-energy landscape $ΔG(Λ;T,μ)$ and the corresponding activation free energy $ΔG^{\\ddagger}$. We compute these quantities using both hyperplane-constrained thermodynamic integration via a mean force relation and a two-state chemical-potential integration, denoted TSCPI. The latter requires sampling only the initial and transition states; a single chemical-potential integration then yields $ΔG^{\\ddagger}(T,μ)$ across a wide $μ$ range, enabling rapid mapping over temperature and chemical potential. Applied to vacancy diffusion in FCC, BCC, and HCP metals with H (including in plane and cross plane diffusion in Zr) and in BCC W with He, both free energy routes agree with diffusion coefficients from molecular dynamics mean square displacements. The resulting maps reveal regimes of suppression and enhancement, including a crossover from suppression to enhancement with increasing hydrogen concentration. A site occupancy analysis links barrier shifts to state dependent site spectrum changes and transferable interstitial interaction terms.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.23564",
  "author_total": 6,
  "authors": [
    {
      "name": "Shihao Zhang"
    },
    {
      "name": "Shihao Zhu"
    },
    {
      "name": "Junping Du"
    },
    {
      "name": "Shuhei Shinzato"
    },
    {
      "name": "Ju Li"
    },
    {
      "name": "Shigenobu Ogata"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/254ax04dc05rd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.23564",
  "fulltext_url": null,
  "id": "254ax04dc05rd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.23564",
  "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",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2505|Fusion materials and technologies"
    ]
  ],
  "openalex": "W7214024563",
  "pdf_url": "https://arxiv.org/pdf/2609.23564",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/254ax04dc05rd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2609.23564",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.23564"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Dual Role of Mobile Interstitials in Defect Kinetics: From Retardation to Acceleration",
  "title_text": "Dual Role of Mobile Interstitials in Defect Kinetics: From Retardation to Acceleration",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/254ax04dc05rd",
  "venue": "arXiv",
  "versions": []
}