CrO3
Chromium trioxide · Chromic anhydride
Chromium trioxide is a reactive, semiconducting transition metal oxide frequently utilized as a potent oxidizing agent and industrial catalyst.

About Chromium trioxide
Chromium trioxide is a high-valent transition metal oxide characterized by its semiconducting electronic structure. As a metastable compound, it exhibits significant chemical reactivity, making it a powerful oxidizing agent widely utilized in synthetic chemistry and surface treatment processes. Its unique coordination environment allows it to participate in complex catalytic cycles, serving as a critical precursor for various industrial applications. The material is valued for its ability to facilitate redox transformations, positioning it as a specialized component within the broader landscape of oxide-based catalysts.
Key Properties
Cross-validated computational properties for Chromium trioxide, 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 CrO3. 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 CrO3, 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. |
|---|---|---|---|---|---|
| Ama2 (No. 40) | orthorhombic | 2.27 | 0.0462 | -7.635 | 2.89 |
| Ama2 (No. 40) | orthorhombic | 2.04 | 0.0566 | -7.625 | 2.69 |
| C2/c (No. 15) | monoclinic | 2.34 | 0.0601 | -7.621 | 2.58 |
| Pna21 (No. 33) | orthorhombic | 1.64 | 0.0772 | -7.604 | 2.58 |
| P21/c (No. 14) | monoclinic | 1.91 | 0.0777 | -7.604 | 2.22 |
| Pnma (No. 62) | orthorhombic | 1.36 | 0.0986 | -7.583 | 2.59 |
| Amm2 (No. 38) | orthorhombic | 1.67 | 0.1033 | -7.578 | 2.60 |
| P21 (No. 4) | monoclinic | 1.33 | 0.2028 | -7.479 | 3.54 |
| Pm-3m (No. 221) | cubic | 0.00 | 0.4022 | -7.279 | 3.37 |
| P63cm (No. 185) | hexagonal | 0.00 | 0.7855 | -6.896 | 3.20 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.9362 | -6.745 | 3.07 |
| Pm-3m (No. 221) | — | — | — | — | — |
Applications
Where Chromium trioxide is used.
Frequently Asked Questions
Common questions about Chromium trioxide, answered from cross-validated data.
What is CrO3?
Chromium trioxide is a reactive, semiconducting transition metal oxide frequently utilized as a potent oxidizing agent and industrial catalyst.
What is CrO3 used for?
What is the band gap of CrO3?
Is CrO3 a metal, semiconductor, or insulator?
Is CrO3 thermodynamically stable?
What is the crystal structure of CrO3?
What is the density of CrO3?
How many polymorphs of CrO3 are known?
What elements does CrO3 contain?
Where does the data for CrO3 come from?
How It Compares
Within the spinel oxide catalysts class.
Unlike the highly stable, insulating MgAl2O4 or the robust binary oxides like NiO and ZnO, CrO3 is distinguished by its metastable nature and heightened chemical activity. While perovskite-structured members like LaMnO3 or LaNiO3 are often investigated for their collective electronic phenomena, CrO3 is primarily leveraged for its aggressive oxidative capacity, setting it apart from the more structurally inert members of the spinel and oxide catalyst families.
Related Compounds
Other Spinel Oxide Catalysts 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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