CaI2
Calcium iodide · calcium diiodide
Calcium iodide is an ionic compound composed of calcium and iodine. It is primarily used in medical applications as an expectorant and in various chemical synthesis processes.
CaI
Overview
Key Properties
Cross-validated computational properties for Calcium iodide, 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.
3.90 eV
Range across DFT structures
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.
0.000 eV/atom
Best (lowest) across sources
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.
On hull (stable)
2 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
56
3 databases, 15 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for CaI2, 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. |
|---|---|---|---|---|---|
| P-3m1 (No. 164) | trigonal | 3.90 | 0.0000 | -3.579 | 3.81 |
| P-1 (No. 2) | Triclinic | — | — | — | 5.54 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.56 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.36 |
| P-1 (No. 2) | Triclinic | — | — | — | 5.46 |
| C2/m (No. 12) | Monoclinic | — | — | — | 4.57 |
| Fmmm (No. 69) | Orthorhombic | — | — | — | 4.23 |
| P21/m (No. 11) | Monoclinic | — | — | — | 3.79 |
| Cmcm (No. 63) | Orthorhombic | — | — | — | 3.51 |
| Cmcm (No. 63) | Orthorhombic | — | — | — | 3.53 |
| Amm2 (No. 38) | Orthorhombic | — | — | — | 6.79 |
| Amm2 (No. 38) | Orthorhombic | — | — | — | 4.13 |
Uses
Applications
Where Calcium iodide is used.
Pharmaceutical expectorantsPhotographyChemical synthesisFood additives
Reference
Frequently Asked Questions
Common questions about Calcium iodide, answered from cross-validated data.
What is CaI2?
Calcium iodide is an ionic compound composed of calcium and iodine. It is primarily used in medical applications as an expectorant and in various chemical synthesis processes.
More questions
What is CaI2 used for?
Calcium iodide (CaI2) is used in pharmaceutical expectorants, photography, chemical synthesis, and food additives.
What is the band gap of CaI2?
Calcium iodide (CaI2) has a DFT-computed band gap of 3.90 eV across 56 reported structures.
Is CaI2 a metal, semiconductor, or insulator?
With a wide band gap up to 3.90 eV it is an insulator / wide-band-gap material.
Is CaI2 thermodynamically stable?
Yes — Calcium iodide (CaI2) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of CaI2?
The lowest-energy reported polymorph of Calcium iodide (CaI2) is trigonal symmetry, space group P-3m1 (No. 164).
What is the density of CaI2?
The computed density of the ground-state structure of Calcium iodide (CaI2) is 3.81 g/cm³.
How many polymorphs of CaI2 are known?
56 structures of CaI2 are reported across 3 databases, spanning 15 distinct space groups.
What elements does CaI2 contain?
Calcium iodide (CaI2) contains Ca and I (2 elements).
Where does the data for CaI2 come from?
CaI2 data is cross-referenced from materials_project, mpaloe.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
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