CoAs2
skutterudite · cobalt diarsenide
CoAs2 is a stable, semiconducting skutterudite material used primarily in the study and development of thermoelectric energy conversion technologies.
About skutterudite
CoAs2 is a prominent member of the skutterudite family, characterized by its semiconducting electronic nature and robust thermodynamic stability. As a material situated on the convex hull, it serves as a foundational structure for understanding the complex interplay between atomic arrangement and carrier transport in pnictide-based systems. Its structural integrity makes it a subject of extensive investigation for high-performance energy applications. The compound is highly regarded for its potential in solid-state thermal management, where its ability to manipulate heat and electrical charge is of primary interest. Its widespread presence in materials databases underscores its importance as a baseline for exploring the thermoelectric potential of transition metal pnictides.
Key Properties
Cross-validated computational properties for skutterudite, 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.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of CoAs2. 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 CoAs2, 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. |
|---|---|---|---|---|---|
| — | — | 0.15 | 0.0000 | -0.330 | — |
| P21/c (No. 14) | monoclinic | 0.12 | 0.0000 | -14.507 | 7.55 |
| P21/c (No. 14) | monoclinic | 0.08 | 0.0000 | -0.303 | — |
| Pnnm (No. 58) | orthorhombic | 0.00 | 0.0183 | -0.285 | — |
| Pnnm (No. 58) | orthorhombic | 0.00 | 0.0197 | -14.487 | 7.54 |
| — | — | 0.00 | 0.0198 | -0.311 | — |
| — | — | 0.00 | 0.1801 | -0.150 | — |
| — | — | 0.00 | 0.3067 | -0.024 | — |
| — | — | 0.00 | 1.3457 | 1.015 | — |
| C2 (No. 5) | monoclinic | — | — | — | 5.82 |
| P21/m (No. 11) | monoclinic | — | — | — | 6.84 |
| P1 (No. 1) | triclinic | — | — | — | 5.53 |
Applications
Where skutterudite is used.
Frequently Asked Questions
Common questions about skutterudite, answered from cross-validated data.
What is CoAs2?
CoAs2 is a stable, semiconducting skutterudite material used primarily in the study and development of thermoelectric energy conversion technologies.
What is CoAs2 used for?
What is the band gap of CoAs2?
Is CoAs2 a metal, semiconductor, or insulator?
Is CoAs2 thermodynamically stable?
What is the crystal structure of CoAs2?
What is the density of CoAs2?
How many polymorphs of CoAs2 are known?
What elements does CoAs2 contain?
Where does the data for CoAs2 come from?
How It Compares
Within the skutterudite thermoelectrics class.
Within the diverse group of skutterudite-related pnictides, CoAs2 stands out for its structural stability compared to siblings like FeP2 or NiP2. While many materials in this class are explored for their tunable electronic properties, CoAs2 provides a reliable framework for studying the intrinsic behavior of cobalt-based pnictides, often serving as a benchmark for evaluating the thermoelectric efficiency of more complex, doped variants.
Related Compounds
Other Skutterudite Thermoelectrics 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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