CoI2
cobalt(II) iodide · cobaltous iodide
Cobalt(II) iodide is a stable, metallic inorganic compound frequently studied for its structural properties and chemical behavior.
About cobalt(II) iodide
Cobalt(II) iodide is a robust inorganic compound that sits firmly on the thermodynamic convex hull, indicating high stability under standard conditions. As a metallic material, it represents a distinct electronic configuration within the broader family of transition metal halides.
With extensive documentation across multiple structural databases, this compound is a well-characterized subject of materials research. Its reliable formation and structural consistency make it a valuable reference point for studying the behavior of cobalt-based halides in various chemical environments.
Key Properties
Cross-validated computational properties for cobalt(II) iodide, 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 CoI2, 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. |
|---|---|---|---|---|---|
| P-3m1 (No. 164) | trigonal | 0.00 | 0.0000 | -3.635 | 5.97 |
| Pmma (No. 51) | Orthorhombic | — | — | — | 8.10 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.06 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.49 |
| C2/m (No. 12) | Monoclinic | — | — | — | 7.40 |
| C2/c (No. 15) | Monoclinic | — | — | — | 6.72 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.76 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.69 |
| Pmma (No. 51) | Orthorhombic | — | — | — | 5.37 |
| Cm (No. 8) | Monoclinic | — | — | — | 4.98 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.31 |
| C2/m (No. 12) | Monoclinic | — | — | — | 4.76 |
Applications
Where cobalt(II) iodide is used.
Frequently Asked Questions
Common questions about cobalt(II) iodide, answered from cross-validated data.
What is CoI2?
Cobalt(II) iodide is a stable, metallic inorganic compound frequently studied for its structural properties and chemical behavior.
What is CoI2 used for?
What is the band gap of CoI2?
Is CoI2 a metal, semiconductor, or insulator?
Is CoI2 thermodynamically stable?
What is the crystal structure of CoI2?
What is the density of CoI2?
How many polymorphs of CoI2 are known?
What elements does CoI2 contain?
Where does the data for CoI2 come from?
How It Compares
As a standalone representative of its specific chemical class in this context, cobalt(II) iodide serves as a fundamental benchmark for understanding the structural and electronic properties of metal diiodides.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
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