CuI2
CuI2 is a metastable metallic compound consisting of copper and iodine that is primarily studied for its complex structural properties.
About CuI2
CuI2 is a metastable inorganic compound composed of copper and iodine. Its electronic character is defined as metallic, distinguishing it from more common insulating or semiconducting copper halides. Due to its metastable nature, it represents a complex phase that challenges traditional synthesis methods and offers a unique subject for structural analysis.
This compound is of significant interest in fundamental materials science, particularly for researchers investigating non-equilibrium phases. With numerous reported structures across multiple databases, it serves as a critical case study for understanding the stability limits of copper-based binary systems.
Key Properties
Cross-validated computational properties for CuI2, 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 CuI2. 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 CuI2, 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. |
|---|---|---|---|---|---|
| — | — | 0.00 | 0.0003 | -0.233 | — |
| — | — | 0.00 | 0.0069 | -0.226 | — |
| — | — | 0.00 | 0.0567 | -0.176 | — |
| — | — | 0.00 | 0.0605 | -0.173 | — |
| — | — | 0.00 | 0.0607 | -0.172 | — |
| — | — | 0.00 | 0.0815 | -0.152 | — |
| — | — | 0.00 | 0.0859 | -0.147 | — |
| — | — | 0.00 | 0.0870 | -0.146 | — |
| — | — | 0.00 | 0.0917 | -0.141 | — |
| P4/mmm (No. 123) | tetragonal | 0.00 | 0.0931 | -2.543 | 4.29 |
| P4/mmm (No. 123) | tetragonal | 0.00 | 0.0984 | -2.538 | 4.03 |
| — | — | 0.00 | 0.1044 | -0.129 | — |
Applications
Where CuI2 is used.
Frequently Asked Questions
Common questions about CuI2, answered from cross-validated data.
What is CuI2?
CuI2 is a metastable metallic compound consisting of copper and iodine that is primarily studied for its complex structural properties.
What is CuI2 used for?
What is the band gap of CuI2?
Is CuI2 a metal, semiconductor, or insulator?
Is CuI2 thermodynamically stable?
What is the crystal structure of CuI2?
What is the density of CuI2?
How many polymorphs of CuI2 are known?
What elements does CuI2 contain?
Where does the data for CuI2 come from?
How It Compares
As a metastable metallic phase, CuI2 stands out for its structural diversity and unconventional electronic behavior compared to more stable, insulating binary halides typically found in this chemical class.
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.
Analyze CuI2 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 85 source databases.
Explore the Platform →