MgH2
Magnesium hydride · Magnesium dihydride
Magnesium hydride is a stable, insulating inorganic compound widely researched for its potential to store large quantities of hydrogen in a solid state.
About Magnesium hydride
Magnesium hydride is a thermodynamically stable binary hydride that serves as a cornerstone in the study of hydrogen storage materials. As a wide-band-gap insulator, it possesses a high hydrogen density, making it a subject of extensive structural investigation across numerous experimental and computational databases.
Its significance lies in its potential for high-capacity hydrogen sequestration, where its stability is both a benefit for safety and a challenge for kinetic release. Researchers frequently utilize this compound to understand the fundamental mechanisms governing solid-state hydrogen storage systems.
Key Properties
Cross-validated computational properties for Magnesium hydride, aggregated across 3 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Reported Structures
Lowest-energy structures reported for MgH2, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| P42/mnm (No. 136) | tetragonal | 3.71 | 0.0000 | -3.090 | 1.46 |
| Pbcn (No. 60) | orthorhombic | 3.63 | 0.0019 | -3.088 | 1.48 |
| Pa-3 (No. 205) | cubic | 3.00 | 0.0353 | -3.054 | 1.59 |
| Pca21 (No. 29) | orthorhombic | 2.35 | 0.0438 | -3.046 | 1.63 |
| Pbca (No. 61) | orthorhombic | 2.07 | 0.0459 | -3.044 | 1.63 |
| Pnma (No. 62) | orthorhombic | 1.95 | 0.0817 | -3.008 | 1.77 |
| Fm-3m (No. 225) | cubic | 0.00 | 0.1094 | -2.980 | 1.62 |
| P42/mnm (No. 136) | — | — | — | — | — |
| C2/m (No. 12) | Monoclinic | — | — | — | 1.70 |
| Pa-3 (No. 205) | Cubic | — | — | — | 1.58 |
| Pa-3 (No. 205) | — | — | — | — | — |
| Pnma (No. 62) | — | — | — | — | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting MgH2.
Applications
Where Magnesium hydride is used.
Frequently Asked Questions
Common questions about Magnesium hydride, answered from cross-validated data.
What is MgH2?
Magnesium hydride is a stable, insulating inorganic compound widely researched for its potential to store large quantities of hydrogen in a solid state.
What is MgH2 used for?
What is the band gap of MgH2?
Is MgH2 a metal, semiconductor, or insulator?
Is MgH2 thermodynamically stable?
What is the crystal structure of MgH2?
What is the density of MgH2?
How many polymorphs of MgH2 are known?
How is MgH2 synthesized?
What elements does MgH2 contain?
Where does the data for MgH2 come from?
How It Compares
Within the hydrogen storage hydrides class.
Within the class of hydrogen storage hydrides, MgH2 is distinguished by its robust thermodynamic stability compared to more reactive or volatile counterparts like BH3 or AlH3. While simple ionic hydrides such as LiH or CaH2 often exhibit different bonding characteristics, MgH2 occupies a unique niche due to its favorable weight-to-hydrogen ratio and its status as one of the most thoroughly documented materials in the field.
Related Compounds
Other Hydrogen Storage Hydrides in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
- mpaloe — Data from mpaloe.
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