EuI2
europium(II) iodide · europium diiodide
Europium(II) iodide is a stable semiconducting material composed of europium and iodine that is primarily utilized in advanced optical and sensing research.

About europium(II) iodide
Europium(II) iodide is a stable inorganic halide compound that exhibits semiconducting electronic behavior. Its position on the thermodynamic convex hull highlights its structural robustness, making it a reliable candidate for materials research where chemical stability is paramount.
Due to its unique electronic configuration, this compound is primarily investigated for its potential in specialized optical applications. It serves as a foundational material for studying the interaction between rare-earth ions and halide lattices, contributing to the broader understanding of lanthanide-based semiconductors.
Key Properties
Cross-validated computational properties for europium(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.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of EuI2. 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 EuI2, 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. |
|---|---|---|---|---|---|
| Pnma (No. 62) | orthorhombic | 1.33 | 0.0000 | -6.320 | 5.29 |
| P21/c (No. 14) | monoclinic | 1.41 | 0.0084 | -6.312 | 5.39 |
| Pbca (No. 61) | orthorhombic | 1.45 | 0.0114 | -6.309 | 5.44 |
| Imma (No. 74) | Orthorhombic | — | — | — | 4.48 |
| No. 0 | unknown | — | — | — | 1.37 |
| Imma (No. 74) | Orthorhombic | — | — | — | 4.14 |
| R3m (No. 160) | Trigonal | — | — | — | 5.20 |
| Cm (No. 8) | Monoclinic | — | — | — | 4.45 |
| Cm (No. 8) | Monoclinic | — | — | — | 8.01 |
| Pnma (No. 62) | Orthorhombic | — | — | — | 5.29 |
| Pbca (No. 61) | Orthorhombic | — | — | — | 5.47 |
| Imma (No. 74) | Orthorhombic | — | — | — | 8.56 |
Applications
Where europium(II) iodide is used.
Frequently Asked Questions
Common questions about europium(II) iodide, answered from cross-validated data.
What is EuI2?
Europium(II) iodide is a stable semiconducting material composed of europium and iodine that is primarily utilized in advanced optical and sensing research.
What is EuI2 used for?
What is the band gap of EuI2?
Is EuI2 a metal, semiconductor, or insulator?
Is EuI2 thermodynamically stable?
What is the crystal structure of EuI2?
What is the density of EuI2?
How many polymorphs of EuI2 are known?
What elements does EuI2 contain?
Where does the data for EuI2 come from?
How It Compares
As a stable representative of the europium-iodide system, this compound serves as a critical reference point for understanding the structural and electronic trends within rare-earth dihalides.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
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