KMn4O8
KMn4O8 is a semiconducting manganese oxide compound investigated for its potential as a catalyst in oxygen-evolution reactions.

About KMn4O8
KMn4O8 is a complex manganese-based oxide that functions as a semiconducting catalyst for the oxygen-evolution reaction. Its structural configuration and electronic properties make it a subject of interest for researchers seeking efficient, earth-abundant alternatives for water splitting and energy storage technologies.
As a near-hull compound, it is considered thermodynamically accessible and likely synthesizable under controlled laboratory conditions. The material benefits from a rich history of structural characterization, providing a solid foundation for its potential integration into electrochemical devices where stable oxide catalysts are required.
Key Properties
Cross-validated computational properties for KMn4O8, aggregated across 4 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 KMn4O8, 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. |
|---|---|---|---|---|---|
| C2/m (No. 12) | monoclinic | 0.19 | 0.0068 | -7.888 | 3.23 |
| I4/m (No. 87) | tetragonal | 0.00 | 0.0078 | -7.887 | 4.61 |
| R-3m (No. 166) | trigonal | 0.00 | 0.0528 | -10.733 | 3.54 |
| P1 (No. 1) | triclinic | 0.02 | 0.2336 | -7.661 | 3.81 |
| P1 (No. 1) | triclinic | 0.24 | 0.3884 | -7.506 | 4.42 |
| P1 (No. 1) | — | — | — | — | — |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.23 |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.76 |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.59 |
| I4/m (No. 87) | Tetragonal | — | — | — | 4.31 |
| I4/m (No. 87) | Tetragonal | — | — | — | 4.86 |
| I4/m (No. 87) | Tetragonal | — | — | — | 4.57 |
Applications
Where KMn4O8 is used.
Frequently Asked Questions
Common questions about KMn4O8, answered from cross-validated data.
What is KMn4O8?
KMn4O8 is a semiconducting manganese oxide compound investigated for its potential as a catalyst in oxygen-evolution reactions.
What is KMn4O8 used for?
What is the band gap of KMn4O8?
Is KMn4O8 a metal, semiconductor, or insulator?
Is KMn4O8 thermodynamically stable?
What is the crystal structure of KMn4O8?
What is the density of KMn4O8?
How many polymorphs of KMn4O8 are known?
What elements does KMn4O8 contain?
Where does the data for KMn4O8 come from?
How It Compares
Within the oxide oxygen-evolution catalysts class.
Within the diverse landscape of oxide oxygen-evolution catalysts, KMn4O8 occupies a distinct niche compared to well-known battery materials like LiMn2O4 or LiCoO2. While those lithium-based oxides are optimized for ion intercalation, KMn4O8 focuses on the catalytic surface processes necessary for oxygen evolution, positioning it alongside transition metal oxides like LaMnO3 in the search for high-performance, non-precious metal electrocatalysts.
Related Compounds
Other Oxide Oxygen-Evolution 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.
- omat24 — Data from OMat24 (Meta FAIR). Cite: Barroso-Luque et al., arXiv 2410.12771 (2024).
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