AlH3
Aluminum hydride · Alane
Aluminum hydride is a stable, insulating solid used primarily for hydrogen storage and as a chemical reducing agent.
About Aluminum hydride
Aluminum hydride, commonly known as alane, is a significant hydrogen storage hydride characterized by its wide-band-gap insulating electronic structure. As a thermodynamically stable compound residing on the convex hull, it represents a robust candidate for high-density hydrogen containment systems.
Its structural diversity is notable, with numerous reported configurations across various databases. This complexity underscores its role as a versatile material in chemical synthesis and advanced fuel research, where its ability to store and release hydrogen efficiently is of primary interest.
Key Properties
Cross-validated computational properties for Aluminum hydride, aggregated across 5 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.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of AlH3. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for AlH3, 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. |
|---|---|---|---|---|---|
| — | — | 3.45 | 0.0000 | -0.010 | — |
| R-3c (No. 167) | trigonal | 2.46 | 0.0000 | -0.102 | — |
| R-3c (No. 167) | trigonal | 2.20 | 0.0000 | -4.348 | 1.52 |
| Cmcm (No. 63) | orthorhombic | 3.04 | 0.0042 | -4.344 | 1.28 |
| — | — | 3.57 | 0.0067 | -0.003 | — |
| Fd-3m (No. 227) | cubic | 3.11 | 0.0100 | -4.338 | 1.10 |
| Cmcm (No. 63) | orthorhombic | 3.34 | 0.0121 | -0.090 | — |
| — | — | 2.84 | 0.0121 | 0.002 | — |
| — | — | 3.39 | 0.0128 | 0.003 | — |
| Pnnm (No. 58) | orthorhombic | 3.19 | 0.0146 | -4.333 | 1.32 |
| Pnnm (No. 58) | orthorhombic | 3.45 | 0.0189 | -0.083 | — |
| Pm-3m (No. 221) | cubic | 1.61 | 0.0221 | -0.080 | — |
Applications
Where Aluminum hydride is used.
Patent Landscape
3 patents reference AlH3 or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 4083933 | Process for preparing AlH.sub.3 (PO.sub.4).sub.2 .multidot.3H.sub.2 O | — | — |
| 4021528 | Process for preparing AlH.sub.3 (PO.sub.4).sub.2.3 H.sub.2 O | — | — |
| 5565183 | Method for the preparation of aluminum hydride (AlH.sub.3) by reacting magnesium hydride with aluminum halide | — | — |
Frequently Asked Questions
Common questions about Aluminum hydride, answered from cross-validated data.
What is AlH3?
Aluminum hydride is a stable, insulating solid used primarily for hydrogen storage and as a chemical reducing agent.
What is AlH3 used for?
What is the band gap of AlH3?
Is AlH3 a metal, semiconductor, or insulator?
Is AlH3 thermodynamically stable?
What is the crystal structure of AlH3?
How many polymorphs of AlH3 are known?
What elements does AlH3 contain?
Where does the data for AlH3 come from?
How It Compares
Within the hydrogen storage hydrides class.
Within the class of hydrogen storage hydrides, alane stands out for its unique stability profile compared to more reactive or volatile counterparts like BH3 or H3N. While simple binary hydrides such as LiH or MgH2 are frequently studied for their basic storage mechanisms, AlH3 offers a distinct balance of density and stability that differentiates it from the alkaline earth metal hydrides like CaH2.
Related Compounds
Other Hydrogen Storage Hydrides in the database.
Data sources & attribution
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
Analyze AlH3 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 85 source databases.
Explore the Platform →