H3N
Ammonia · NH3, Azane
H3N is a stable, insulating hydride of nitrogen and hydrogen that serves as a vital industrial chemical and a potential medium for hydrogen storage.

About Ammonia
H3N, commonly known as ammonia, is a fundamental hydrogen storage hydride characterized by its wide-gap insulating electronic structure. As a thermodynamically stable compound residing on the convex hull, it serves as a robust chemical platform for energy storage and synthesis.
Its significance extends beyond simple storage, as it acts as a primary precursor in the production of nitrogen-based fertilizers and various industrial chemicals. The compound's stability and high hydrogen density make it a subject of extensive structural research across multiple databases.
Key Properties
Cross-validated computational properties for Ammonia, 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 H3N, 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. |
|---|---|---|---|---|---|
| P213 (No. 198) | cubic | 4.34 | 0.0000 | -5.222 | 0.92 |
| P212121 (No. 19) | orthorhombic | 4.45 | 0.0038 | -5.219 | 0.99 |
| P213 (No. 198) | cubic | 3.73 | 0.0220 | -5.200 | 0.74 |
| Amm2 (No. 38) | Orthorhombic | — | — | — | 2.16 |
| C2 (No. 5) | Monoclinic | — | — | — | 1.65 |
| P-1 (No. 2) | Triclinic | — | — | — | 1.95 |
| P1 (No. 1) | Triclinic | — | — | — | 1.67 |
| P-1 (No. 2) | Triclinic | — | — | — | 1.97 |
| C2 (No. 5) | Monoclinic | — | — | — | 1.61 |
| P-1 (No. 2) | Triclinic | — | — | — | 1.78 |
| P21/c (No. 14) | Monoclinic | — | — | — | 1.27 |
| P-1 (No. 2) | Triclinic | — | — | — | 1.45 |
Applications
Where Ammonia is used.
Frequently Asked Questions
Common questions about Ammonia, answered from cross-validated data.
What is H3N?
H3N is a stable, insulating hydride of nitrogen and hydrogen that serves as a vital industrial chemical and a potential medium for hydrogen storage.
What is H3N used for?
What is the band gap of H3N?
Is H3N a metal, semiconductor, or insulator?
Is H3N thermodynamically stable?
What is the crystal structure of H3N?
What is the density of H3N?
How many polymorphs of H3N are known?
What elements does H3N contain?
Where does the data for H3N come from?
How It Compares
Within the hydrogen storage hydrides class.
Within the class of hydrogen storage hydrides, H3N stands out as a molecular species compared to the more traditional ionic or metallic hydrides like MgH2, CaH2, or LiH. While those solid-state hydrides are often utilized for their reversible hydrogen desorption properties in structural alloys, H3N functions primarily as a high-density liquid or gaseous carrier, offering a distinct chemical pathway for hydrogen delivery and nitrogen-based fuel cycles.
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).
- mpaloe — Data from mpaloe.
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
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