Pm2O3
promethium(III) oxide · promethium oxide
Promethium(III) oxide is a stable, wide-gap insulating compound formed from the radioactive element promethium and oxygen.
About promethium(III) oxide
Promethium(III) oxide is a thermodynamically stable compound formed from the rare radioactive element promethium and oxygen. As an insulating material with a wide electronic band gap, it represents a specialized member of the lanthanide oxide series, characterized by its unique radioactive nature and specific structural arrangements. The compound is notable for its structural diversity, with numerous reported crystalline configurations across materials databases. Its stability on the convex hull underscores its significance in fundamental studies of rare earth chemistry and the behavior of radioactive materials in solid-state systems.
Key Properties
Cross-validated computational properties for promethium(III) oxide, 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.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of Pm2O3. 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 Pm2O3, 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. |
|---|---|---|---|---|---|
| — | — | 4.02 | 0.0000 | -3.677 | — |
| Ia-3 (No. 206) | cubic | 3.77 | 0.0000 | -8.705 | 6.73 |
| C2/m (No. 12) | monoclinic | 3.76 | 0.0000 | -3.644 | — |
| P-3m1 (No. 164) | trigonal | 4.01 | 0.0090 | -3.635 | — |
| C2/m (No. 12) | monoclinic | 3.70 | 0.0115 | -8.694 | 7.36 |
| P-3m1 (No. 164) | trigonal | 3.87 | 0.0123 | -8.693 | 7.50 |
| — | — | 3.97 | 0.0305 | -3.646 | — |
| — | — | 4.00 | 0.0356 | -3.641 | — |
| — | — | 1.17 | 0.9344 | -2.742 | — |
| P4mm (No. 99) | tetragonal | — | — | — | 8.12 |
| Cm (No. 8) | monoclinic | — | — | — | 5.44 |
| Cm (No. 8) | monoclinic | — | — | — | 5.75 |
Applications
Where promethium(III) oxide is used.
Frequently Asked Questions
Common questions about promethium(III) oxide, answered from cross-validated data.
What is Pm2O3?
Promethium(III) oxide is a stable, wide-gap insulating compound formed from the radioactive element promethium and oxygen.
What is Pm2O3 used for?
What is the band gap of Pm2O3?
Is Pm2O3 a metal, semiconductor, or insulator?
Is Pm2O3 thermodynamically stable?
What is the crystal structure of Pm2O3?
What is the density of Pm2O3?
How many polymorphs of Pm2O3 are known?
What elements does Pm2O3 contain?
Where does the data for Pm2O3 come from?
How It Compares
As a member of the lanthanide oxide family, Pm2O3 occupies a unique position due to the inherent radioactivity of the promethium cation, which distinguishes its handling and research requirements from more common stable rare-earth oxides.
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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
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