SeO3
selenium trioxide · selenic anhydride
Selenium trioxide is a semiconducting binary oxide of selenium that is recognized for its potential for synthesis and structural complexity.

About selenium trioxide
Selenium trioxide is a binary oxide of selenium that exhibits semiconducting electronic characteristics. Due to its position near the thermodynamic hull, it is considered a synthesizable compound of significant interest in inorganic chemistry research.
Its structural diversity is evidenced by a large number of reported configurations within material databases. This complexity makes it a compelling subject for studies focused on the fundamental bonding and stability of chalcogen-based oxides.
Key Properties
Cross-validated computational properties for selenium trioxide, 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 SeO3, 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. |
|---|---|---|---|---|---|
| P-421c (No. 114) | tetragonal | 2.43 | 0.0203 | -5.459 | 3.45 |
| P212121 (No. 19) | orthorhombic | 2.20 | 0.1668 | -5.312 | 2.61 |
| P21/m (No. 11) | Monoclinic | — | — | — | 4.15 |
| P-1 (No. 2) | Triclinic | — | — | — | 3.79 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.06 |
| P-31m (No. 162) | Trigonal | — | — | — | 4.87 |
| P21/m (No. 11) | Monoclinic | — | — | — | 5.17 |
| P1 (No. 1) | Triclinic | — | — | — | 4.15 |
| Pm (No. 6) | Monoclinic | — | — | — | 3.60 |
| Pm (No. 6) | Monoclinic | — | — | — | 7.13 |
| Pm (No. 6) | Monoclinic | — | — | — | 4.31 |
| P4mm (No. 99) | Tetragonal | — | — | — | 5.46 |
Applications
Where selenium trioxide is used.
Frequently Asked Questions
Common questions about selenium trioxide, answered from cross-validated data.
What is SeO3?
Selenium trioxide is a semiconducting binary oxide of selenium that is recognized for its potential for synthesis and structural complexity.
What is SeO3 used for?
What is the band gap of SeO3?
Is SeO3 a metal, semiconductor, or insulator?
Is SeO3 thermodynamically stable?
What is the crystal structure of SeO3?
What is the density of SeO3?
How many polymorphs of SeO3 are known?
What elements does SeO3 contain?
Where does the data for SeO3 come from?
How It Compares
As a selenium-based oxide, this compound represents a distinct structural phase within the broader family of chalcogen oxides, serving as a critical reference point for understanding the stability limits of high-oxidation-state selenium compounds.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
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