CrI3
Chromium triiodide · Chromium(III) iodide
Chromium triiodide is a stable, semiconducting chromium halide widely studied for its unique magnetic properties in thin-film and layered forms.

About Chromium triiodide
Chromium triiodide is a thermodynamically stable inorganic compound that exists as a semiconducting material. Its structural characteristics have made it a subject of extensive investigation, particularly within the context of two-dimensional magnetism and layered van der Waals crystals.
Because it sits on the convex hull, this compound exhibits robust stability, which is essential for its role in experimental condensed matter physics. It is primarily utilized as a platform for studying fundamental electronic and magnetic phenomena in thin-film configurations.
Key Properties
Cross-validated computational properties for Chromium 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 CrI3, 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. |
|---|---|---|---|---|---|
| P3112 (No. 151) | trigonal | 1.16 | 0.0000 | -4.279 | 4.94 |
| P-3m1 (No. 164) | Trigonal | — | — | — | 7.55 |
| P1 (No. 1) | Triclinic | — | — | — | 3.75 |
| P1 (No. 1) | Triclinic | — | — | — | 5.49 |
| Pmm2 (No. 25) | Orthorhombic | — | — | — | 9.55 |
| P1 (No. 1) | Triclinic | — | — | — | 3.36 |
| Pm (No. 6) | Monoclinic | — | — | — | 5.09 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.17 |
| Cm (No. 8) | Monoclinic | — | — | — | 4.65 |
| P1 (No. 1) | Triclinic | — | — | — | 9.66 |
| P2/m (No. 10) | Monoclinic | — | — | — | 3.71 |
| P2/m (No. 10) | Monoclinic | — | — | — | 5.72 |
Applications
Where Chromium triiodide is used.
Frequently Asked Questions
Common questions about Chromium triiodide, answered from cross-validated data.
What is CrI3?
Chromium triiodide is a stable, semiconducting chromium halide widely studied for its unique magnetic properties in thin-film and layered forms.
What is CrI3 used for?
What is the band gap of CrI3?
Is CrI3 a metal, semiconductor, or insulator?
Is CrI3 thermodynamically stable?
What is the crystal structure of CrI3?
What is the density of CrI3?
How many polymorphs of CrI3 are known?
What elements does CrI3 contain?
Where does the data for CrI3 come from?
How It Compares
As a prominent layered halide, Chromium triiodide serves as a foundational reference point for the study of intrinsic magnetism in low-dimensional systems, setting the standard for how semiconducting halides can be manipulated to exhibit long-range magnetic order.
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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