{
  "abstract": "Double perovskite hydrides have been identified as promising candidates in solid-state hydrogen storage applications. In the current study, we have explored the structural, hydrogen storage, electronic, optical, mechanical, and thermodynamic characteristics of K₂LiMgH₆ and K₂LiCaH₆. Their structural and thermodynamic stability is demonstrated by the tolerance factors (0.93 and 0.92) being near unity and negative enthalpies of formation (-0.33 and -0.28 eV). Moreover, thermal and dynamic stability are also ensured by AIMD simulations and positive frequencies of phonon band structures. Their gravimetric hydrogen storage capacities are determined to be 5.23 wt% and 4.61 wt%, with corresponding desorption temperatures of 245 K and 208 K, respectively. The electronic analysis shows semiconducting character for K₂LiMgH₆ and metallic character for K₂LiCaH₆, with electronic states crossing the Fermi level. The existence of a finite bandgap guarantees that optical absorption will begin in the UV, which is advantageous for controlled photon-assisted hydrogen release. The mechanical aspects show their brittle nature, with well-defined thermodynamic properties. These results, combined with favorable thermodynamic and hydrogen storage characteristics, establish K₂LiMgH₆ and K₂LiCaH₆ as potential materials for next-generation hydrogen storage technologies. The mineral derived elements (Mg, Ca) tune the hydrogen storage capacity and other physical aspects.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physics, Division of Science and Technology, University of Education Lahore Punjab 54770 Pakistan gmmustafa1025@gmail.com.",
    "Department of Chemistry, College of Sciences, Princess Nourah bint Abdulrahman University (PNU) PO Box 84428 Riyadh 11671 Saudi Arabia.",
    "Department of Science and Technology, University College at Nairiyah, University of Hafr Al Batin (UHB) Nairiyah 31981 Saudi Arabia.",
    "Department of Physics, College of Science, Qassim University Buridah 51452 Saudi Arabia.",
    "Center for Scientific Research and Entrepreneurship, Northern Border University 73213 Arar Saudi Arabia.",
    "Physics Department, Faculty of Science, Islamic University of Madinah Madinah 42351 Saudi Arabia.",
    "Basic and Applied Scientific Research Center, Imam Abdulrahman Bin Faisal University P. O. Box 1982 Dammam 31441 Saudi Arabia.",
    "Department of Physics, College of Science, Imam Abdulrahman Bin Faisal University P. O. Box 1982 Dammam 31441 Saudi Arabia."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Kirran Siddique"
    },
    {
      "affs": [
        0
      ],
      "name": "Ghulam M Mustafa",
      "orcid": "0009-0003-5054-5236"
    },
    {
      "affs": [
        1
      ],
      "name": "Murefah Mana Al-Anazy"
    },
    {
      "affs": [
        2
      ],
      "name": "Noura Dawas Alkhaldi"
    },
    {
      "affs": [
        3
      ],
      "name": "Abdelkareem Almeshal",
      "orcid": "0000-0001-6601-0816"
    },
    {
      "affs": [
        4
      ],
      "name": "Ali El-Rayyes",
      "orcid": "0000-0003-3847-1329"
    },
    {
      "affs": [
        5
      ],
      "name": "Mohd Taukeer Khan"
    },
    {
      "affs": [
        6,
        7
      ],
      "name": "Q Mahmood"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fxk6nxqpd3zkm.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra08143f",
  "fulltext_url": "https://europepmc.org/articles/PMC13693644",
  "id": "fxk6nxqpd3zkm",
  "issns": [
    "2046-2069"
  ],
  "landing_url": "https://europepmc.org/article/MED/42921234",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "2505|Hydrogen Storage and Materials"
    ]
  ],
  "openalex": "W7223408462",
  "pdf_url": "https://europepmc.org/articles/PMC13693644?pdf=render",
  "pmcid": "PMC13693644",
  "pmid": "42921234",
  "published": "2026-10-23",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/fxk6nxqpd3zkm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:33Z",
      "native_id": "MED:42921234",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42921234"
    },
    {
      "first_seen": "2026-11-07T12:23:47Z",
      "native_id": "PMC13693644",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra08143f"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Hydrogen Storage and Materials",
      "subfield": "materials-polymers"
    }
  ],
  "title": "First-principles investigation of hydrogen storage capacity, electronic, optical, mechanical, and thermodynamic properties of alkaline-metal-based K₂LiXH₆ (X = Mg, Ca) hydrides.",
  "title_text": "First-principles investigation of hydrogen storage capacity, electronic, optical, mechanical, and thermodynamic properties of alkaline-metal-based K₂LiXH₆ (X = Mg, Ca) hydrides.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T12:21:08Z",
  "url": "https://research.draconitic.com/paper/fxk6nxqpd3zkm",
  "venue": "RSC advances",
  "versions": []
}