I
Iodine · I2
Iodine is a thermodynamically stable, semiconducting element recognized for its significant structural diversity and widespread utility in industrial and chemical processes.
About Iodine
Iodine is a fundamental chemical element that exists as a thermodynamically stable solid under standard conditions. It is characterized by its semiconducting electronic nature, which distinguishes it from many other non-metallic elements and influences its reactivity in various chemical environments.
This element is highly valued for its structural complexity, as evidenced by the large number of reported crystalline arrangements across major databases. Its role as a versatile chemical building block makes it essential for high-performance applications ranging from advanced manufacturing to specialized chemical synthesis.
Key Properties
Cross-validated computational properties for Iodine, aggregated across 6 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 I. 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 I, 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. |
|---|---|---|---|---|---|
| — | — | 1.41 | 0.0000 | -0.007 | — |
| Cmce (No. 64) | orthorhombic | 1.01 | 0.0000 | -1.524 | 4.84 |
| Cmce (No. 64) | orthorhombic | 0.92 | 0.0000 | 0.000 | — |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0000 | 0.062 | — |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0000 | 0.058 | — |
| Pm-3m (No. 221) | cubic | 0.00 | 0.0000 | 1.537 | — |
| P4/mmm (No. 123) | tetragonal | 0.00 | 0.0000 | 0.256 | — |
| Immm (No. 71) | orthorhombic | 0.00 | 0.0000 | 0.071 | — |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0000 | 0.084 | — |
| Im-3m (No. 229) | cubic | 0.00 | 0.0000 | 0.363 | — |
| — | — | 0.98 | 0.0074 | 0.000 | — |
| — | — | 0.00 | 0.0495 | 0.042 | — |
Applications
Where Iodine is used.
Frequently Asked Questions
Common questions about Iodine, answered from cross-validated data.
What is I?
Iodine is a thermodynamically stable, semiconducting element recognized for its significant structural diversity and widespread utility in industrial and chemical processes.
What is I used for?
What is the band gap of I?
Is I a metal, semiconductor, or insulator?
Is I thermodynamically stable?
What is the crystal structure of I?
What is the density of I?
How many polymorphs of I are known?
What elements does I contain?
Where does the data for I come from?
How It Compares
As a standalone elemental solid, iodine serves as a primary reference point for understanding halogen chemistry and the transition toward semiconducting behavior in non-metallic crystalline structures.
Data sources & attribution
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
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