Fe4Bi2O9
Fe4Bi2O9 has a DFT band gap of 1.64 eV across 6 reported structures in 1 space group; its reference structure is orthorhombic (Pbam (No. 55)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for Fe4Bi2O9, 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.
1.64 eV
Range across DFT structures · ground state: narrow gap
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.
0.000 eV/atom
Best (lowest) across sources
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.
Stable
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
6
3 databases, 1 space group
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of Fe4Bi2O9. 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.
0.69 / 1.00
Trust tier: medium
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.077 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
3
jarvis, materials_project, oqmd
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for Fe4Bi2O9, 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. |
|---|---|---|---|---|---|
| — | — | 1.64 | 0.0000 | -1.601 | — |
| Pbam (No. 55) | orthorhombic | 1.24 | 0.0117 | -7.420 | 6.36 |
| Pnma (No. 62) | orthorhombic | 2.27 | 0.0171 | -7.414 | 6.13 |
| Pbam (No. 55) | orthorhombic | 0.00 | 0.0770 | -1.344 | — |
| Pbam (No. 55) | orthorhombic | 0.00 | 0.0946 | -1.326 | — |
| Pbam (No. 55) | orthorhombic | — | — | — | 6.52 |
| Pbam (No. 55) | orthorhombic | — | — | — | 6.48 |
| Pbam (No. 55) | orthorhombic | — | — | — | 6.12 |
| Pbam (No. 55) | orthorhombic | — | — | — | 6.28 |
| Pbam (No. 55) | orthorhombic | — | — | — | 6.47 |
Synthesis
Synthesis Routes
Literature-extracted synthesis procedures targeting Fe4Bi2O9.
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Solid State
Procedure available · ceder_solid_state
Reference
Frequently Asked Questions
Common questions about Fe4Bi2O9, answered from cross-validated data.
What is the band gap of Fe4Bi2O9?
Fe4Bi2O9 has a DFT-computed band gap of 1.64 eV across 6 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
More questions
Is Fe4Bi2O9 a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 1.64 eV (a semiconductor). Measured gaps are typically larger.
Is Fe4Bi2O9 thermodynamically stable?
Yes — Fe4Bi2O9 sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of Fe4Bi2O9?
The reference structure of Fe4Bi2O9 is orthorhombic symmetry, space group Pbam (No. 55).
What is the density of Fe4Bi2O9?
The computed density of the ground-state structure of Fe4Bi2O9 is 6.36 g/cm³.
How many polymorphs of Fe4Bi2O9 are known?
6 structures of Fe4Bi2O9 are reported across 3 databases, spanning 1 distinct space group.
How is Fe4Bi2O9 synthesized?
Literature-reported routes for Fe4Bi2O9 include sol gel, solid state (10 procedures documented).
What elements does Fe4Bi2O9 contain?
Fe4Bi2O9 contains Bi, Fe, and O (3 elements).
Where does the data for Fe4Bi2O9 come from?
Fe4Bi2O9 data is cross-referenced from oqmd, materials_project, jarvis, cod, mpaloe.
Explore
Related Compounds
Other Oxide Oxygen-Evolution Catalysts in the database.
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)
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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