Bi4O7
Bi4O7 is a thermodynamically stable bismuth oxide semiconductor used in materials science research.
About Bi4O7
Bi4O7 is a distinct bismuth-based oxide that occupies a stable position on the thermodynamic convex hull. As a semiconducting material, it represents a unique stoichiometry within the bismuth-oxygen binary system, characterized by a well-defined structural framework that has been documented across multiple experimental and computational databases. Its stable nature makes it a subject of interest for researchers investigating the electronic and optoelectronic properties of heavy-metal oxides. The material's ability to maintain structural integrity under various conditions suggests potential utility in specialized electronic components where bismuth-rich phases are required. Its electronic character positions it as a candidate for further exploration in semiconductor device physics.
Key Properties
Cross-validated computational properties for Bi4O7, 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 Bi4O7. 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 Bi4O7, 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. |
|---|---|---|---|---|---|
| — | — | 1.05 | 0.0000 | -1.399 | — |
| P-1 (No. 2) | triclinic | 0.94 | 0.0000 | -6.132 | 9.23 |
| P-1 (No. 2) | triclinic | 0.86 | 0.0000 | -1.264 | — |
| — | — | 0.00 | 0.0961 | -1.303 | — |
| P-43m (No. 215) | cubic | 0.00 | 0.1460 | -1.118 | — |
| P-4b2 (No. 117) | tetragonal | 0.00 | 0.1591 | -5.973 | 9.08 |
| P-1 (No. 2) | triclinic | — | — | — | 8.91 |
| P-1 (No. 2) | triclinic | — | — | — | 9.54 |
| P-4b2 (No. 117) | tetragonal | — | — | — | 9.35 |
| P-4b2 (No. 117) | tetragonal | — | — | — | 9.08 |
| P-1 (No. 2) | triclinic | — | — | — | 9.20 |
| P-4b2 (No. 117) | tetragonal | — | — | — | 9.61 |
Applications
Where Bi4O7 is used.
Frequently Asked Questions
Common questions about Bi4O7, answered from cross-validated data.
What is Bi4O7?
Bi4O7 is a thermodynamically stable bismuth oxide semiconductor used in materials science research.
What is Bi4O7 used for?
What is the band gap of Bi4O7?
Is Bi4O7 a metal, semiconductor, or insulator?
Is Bi4O7 thermodynamically stable?
What is the crystal structure of Bi4O7?
What is the density of Bi4O7?
How many polymorphs of Bi4O7 are known?
What elements does Bi4O7 contain?
Where does the data for Bi4O7 come from?
How It Compares
As a specific bismuth oxide phase, Bi4O7 serves as a critical reference point for understanding the complex phase space of the bismuth-oxygen system. Unlike simpler bismuth oxides, this compound provides a unique structural configuration that bridges the gap between lower and higher oxidation states of bismuth, offering a distinct electronic profile for materials design.
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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