ScI3
Scandium triiodide · Scandium(III) iodide
Scandium triiodide is a stable, semiconducting halide material primarily utilized as a chemical additive in high-performance lighting technologies.

About Scandium triiodide
Scandium triiodide is a semiconducting inorganic compound that exhibits notable thermodynamic stability. As a member of the scandium halide family, it is recognized for its role in high-intensity discharge lamps where it acts as a crucial additive to improve light quality and efficiency. Its structural integrity is well-documented across multiple databases, reflecting its importance in materials science research. Beyond lighting, it serves as a valuable precursor in the synthesis of other scandium-containing materials and organometallic complexes. Its electronic character makes it an interesting subject for studies involving metal-halide interactions and solid-state chemistry.
Key Properties
Cross-validated computational properties for Scandium triiodide, 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.
Reported Structures
Lowest-energy structures reported for ScI3, 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. |
|---|---|---|---|---|---|
| P63/mmc (No. 194) | hexagonal | 1.69 | 0.0000 | -4.200 | 3.66 |
| Amm2 (No. 38) | Orthorhombic | — | — | — | 5.02 |
| Cmcm (No. 63) | Orthorhombic | — | — | — | 5.80 |
| C2/m (No. 12) | Monoclinic | — | — | — | 5.58 |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.88 |
| C2/m (No. 12) | Monoclinic | — | — | — | 9.03 |
| Pm (No. 6) | Monoclinic | — | — | — | 5.61 |
| Pm (No. 6) | Monoclinic | — | — | — | 3.91 |
| Pm (No. 6) | Monoclinic | — | — | — | 9.36 |
| C2/m (No. 12) | Monoclinic | — | — | — | 4.02 |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.90 |
| Amm2 (No. 38) | Orthorhombic | — | — | — | 8.69 |
Applications
Where Scandium triiodide is used.
Frequently Asked Questions
Common questions about Scandium triiodide, answered from cross-validated data.
What is ScI3?
Scandium triiodide is a stable, semiconducting halide material primarily utilized as a chemical additive in high-performance lighting technologies.
What is ScI3 used for?
What is the band gap of ScI3?
Is ScI3 a metal, semiconductor, or insulator?
Is ScI3 thermodynamically stable?
What is the crystal structure of ScI3?
What is the density of ScI3?
How many polymorphs of ScI3 are known?
What elements does ScI3 contain?
Where does the data for ScI3 come from?
How It Compares
As a stable scandium halide, this compound represents a fundamental building block in the study of group 3 iodides. While it stands as a distinct entity within the broader landscape of metal halides, its behavior provides critical insights into the coordination chemistry and thermal properties characteristic of trivalent scandium species.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
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