AsI3
Arsenic triiodide · Arsenous iodide
Arsenic triiodide is a stable, semiconducting compound composed of arsenic and iodine used primarily in chemical synthesis and research.

About Arsenic triiodide
Arsenic triiodide is a well-defined inorganic compound characterized by its semiconducting electronic nature. As a thermodynamically stable phase, it maintains a consistent structural integrity that has been extensively documented across multiple crystallographic databases.
Its significance lies in its utility as a precursor for various chemical syntheses and its role in materials research. The compound's stability makes it a reliable subject for studying the behavior of arsenic-based halides in solid-state applications.
Key Properties
Cross-validated computational properties for Arsenic triiodide, 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 AsI3. 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 AsI3, 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. |
|---|---|---|---|---|---|
| R-3 (No. 148) | trigonal | 2.24 | 0.0000 | -2.789 | 4.45 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.06 |
| P-1 (No. 2) | Triclinic | — | — | — | 3.46 |
| P1 (No. 1) | Triclinic | — | — | — | 6.08 |
| Cm (No. 8) | Monoclinic | — | — | — | 3.63 |
| P1 (No. 1) | Triclinic | — | — | — | 6.71 |
| Cm (No. 8) | Monoclinic | — | — | — | 8.67 |
| Cm (No. 8) | Monoclinic | — | — | — | 3.64 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.55 |
| P1 (No. 1) | Triclinic | — | — | — | 10.07 |
| P1 (No. 1) | Triclinic | — | — | — | 4.10 |
| — | — | — | — | — | 3.96 |
Applications
Where Arsenic triiodide is used.
Frequently Asked Questions
Common questions about Arsenic triiodide, answered from cross-validated data.
What is AsI3?
Arsenic triiodide is a stable, semiconducting compound composed of arsenic and iodine used primarily in chemical synthesis and research.
What is AsI3 used for?
What is the band gap of AsI3?
Is AsI3 a metal, semiconductor, or insulator?
Is AsI3 thermodynamically stable?
What is the crystal structure of AsI3?
What is the density of AsI3?
How many polymorphs of AsI3 are known?
What elements does AsI3 contain?
Where does the data for AsI3 come from?
How It Compares
As a distinct inorganic halide, arsenic triiodide serves as a fundamental reference point for understanding the structural and electronic trends within the broader family of arsenic-based compounds.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- omat24 — Data from OMat24 (Meta FAIR). Cite: Barroso-Luque et al., arXiv 2410.12771 (2024).
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
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