{
  "abstract": "• Mg 2 XH 6 (X = Al/Si) double perovskite hydrides investigated via first-principles DFT. • Mechanical and dynamical stability confirmed by Born criteria and phonon spectra. • Metallic electronic structure with strong dielectric response and optical conductivity. • High gravimetric H 2 capacities of 7.41 wt% (Al) and 7.31 wt% (Si) achieved. • Desorption temperatures of 361.7 K (Al) and 368.0 K (Si) predicted. The escalating worldwide demand for decarbonized energy systems has led to hydrogen being established as a leading candidate owing to its high specific energy and environmentally benign combustion profile. Among the advanced materials for solid-state hydrogen storage, double perovskite hydrides of Mg 2 XH 6 (X = Al/Si) are a promising class of lightweight compounds. Using density functional theory, this study presents a comprehensive computational analysis of the structural, elastic, mechanical, electronic, optical, thermodynamic, and vibrational properties. Moreover, their thermal stability, finite-temperature dynamics via molecular dynamics simulations, and hydrogen-storage performance were evaluated. Tolerance factor calculations revealed that these hydrides adopt stable cubic perovskite configurations, with their negative formation enthalpies providing additional evidence of thermodynamic stability. All hydrides satisfy Born’s mechanical stability criteria and exhibit high stiffness, superior mechanical strength, enhanced hardness, shear resistance, and ductile mechanical characteristics. Electronic band structure calculations demonstrate that both Mg 2 AlH 6 and Mg 2 SiH 6 exhibit metallic behavior using the generalized gradient approximation (GGA) based on the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional. Optical analysis revealed a strong dielectric response, pronounced light–matter interaction, and high optical conductivity, along with superior absorption and excellent photonic performance. Phonon dispersion analysis confirmed the dynamic stability of these compounds. Their thermodynamic parameters and high melting points highlight their overall stability and attractive properties. Furthermore, ab initio molecular dynamics (AIMD) simulations provide compelling evidence of the robust thermal stability of these compounds under realistic conditions. Beyond these attributes, assessments of hydrogen storage capacity exhibit impressive gravimetric contents of 7.41 wt% for Mg 2 AlH 6 and 7.31 wt% for Mg 2 SiH 6 values that exceed the U.S. Department of Energy (DOE) 2025 target of 5.5 wt%. These results highlight the strong potential of these compounds as high-capacity hydrogen-storage materials.",
  "abstract_shown": true,
  "affiliations": [
    "Laboratory of Advanced Materials and Applications (LM2A), Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, B.P.1796 Fez-Atlas, Morocco",
    "Department of Physics, Abou Bakr Belkaid University, Tlemcen 13000, Algeria",
    "Materials Modeling and Simulation Lab, Department of Physics, University of Science & Technology Bannu 28100, Khyber Pakhtunkhwa, Pakistan",
    "Department of Mechanical Engineering, National Taiwan University, Taipei 106319, Taiwan, People’s Republic of China",
    "Department of Applied Mechanics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People’s Republic of China"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Abdelghafour El Mekkaouy"
    },
    {
      "affs": [
        1
      ],
      "name": "Abdellah Hammad"
    },
    {
      "affs": [
        2
      ],
      "name": "Asif Nawaz Khan",
      "orcid": "0009-0000-6663-3183"
    },
    {
      "affs": [
        0
      ],
      "name": "Najat El Gaidi"
    },
    {
      "affs": [
        3
      ],
      "name": "Tesfaye Abebe Geleta",
      "orcid": "0000-0002-6972-5881"
    },
    {
      "affs": [
        1
      ],
      "name": "Younes Mekki"
    },
    {
      "affs": [
        4
      ],
      "name": "Muhammad Usman"
    },
    {
      "affs": [
        0
      ],
      "name": "Rodouan Touti",
      "orcid": "0000-0002-6540-1150"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8k83yevsqcqba.bib",
  "cited_by": 5,
  "doi": "10.1016/j.jma.2026.102110",
  "fulltext_url": null,
  "id": "8k83yevsqcqba",
  "issns": [
    "2213-9567"
  ],
  "landing_url": "https://doi.org/10.1016/j.jma.2026.102110",
  "language": "en",
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2505|Hydrogen Storage and Materials"
    ]
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  "openalex": "W7161270242",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-15",
  "publisher": "Elsevier BV",
  "ris": "https://research.draconitic.com/paper/8k83yevsqcqba.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T13:20:55Z",
      "native_id": "W7161270242",
      "source": "openalex",
      "url": "https://doi.org/10.1016/j.jma.2026.102110"
    }
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  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Hydrogen Storage and Materials",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Thermodynamically stable Mg2XH6 (X = Al, Si) double perovskite hydrides for high-capacity hydrogen storage: A DFT and AIMD study",
  "title_text": "Thermodynamically stable Mg2XH6 (X = Al, Si) double perovskite hydrides for high-capacity hydrogen storage: A DFT and AIMD study",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T13:20:57Z",
  "url": "https://research.draconitic.com/paper/8k83yevsqcqba",
  "venue": "Journal of Magnesium and Alloys",
  "versions": []
}