Cl2
Chlorine · Molecular chlorine, Dichlorine
Chlorine is a highly reactive gaseous element that exists as a diatomic molecule. It is widely utilized in industrial and domestic settings primarily for its potent disinfecting and bleaching properties.
Cl
Overview
Key Properties
Cross-validated computational properties for Chlorine, 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.
2.28–2.65 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)
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
224
5 databases, 9 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for Cl2, 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. |
|---|---|---|---|---|---|
| Cmce (No. 64) | orthorhombic | 2.54 | 0.0000 | -6.152 | 2.09 |
| Cmce (No. 64) | orthorhombic | 2.28 | 0.0000 | -6.152 | 2.09 |
| P42/ncm (No. 138) | tetragonal | 2.65 | 0.0730 | -6.079 | 0.92 |
| P63/mmc (No. 194) | — | — | — | — | — |
| I41/amd (No. 141) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
| Pm-3m (No. 221) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
| I41/amd (No. 141) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
Uses
Applications
Where Chlorine is used.
Water purificationBleaching agentsChemical synthesisProduction of polymersDisinfectants
Reference
Frequently Asked Questions
Common questions about Chlorine, answered from cross-validated data.
What is Cl2?
Chlorine is a highly reactive gaseous element that exists as a diatomic molecule. It is widely utilized in industrial and domestic settings primarily for its potent disinfecting and bleaching properties.
More questions
What is Cl2 used for?
Chlorine (Cl2) is used in water purification, bleaching agents, chemical synthesis, production of polymers, and disinfectants.
What is the band gap of Cl2?
Chlorine (Cl2) has a DFT-computed band gap of 2.28–2.65 eV across 224 reported structures.
Is Cl2 a metal, semiconductor, or insulator?
With a band gap up to 2.65 eV it is a semiconductor.
Is Cl2 thermodynamically stable?
Yes — Chlorine (Cl2) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of Cl2?
The lowest-energy reported polymorph of Chlorine (Cl2) is orthorhombic symmetry, space group Cmce (No. 64).
What is the density of Cl2?
The computed density of the ground-state structure of Chlorine (Cl2) is 2.09 g/cm³.
How many polymorphs of Cl2 are known?
224 structures of Cl2 are reported across 5 databases, spanning 9 distinct space groups.
What elements does Cl2 contain?
Chlorine (Cl2) contains Cl (1 element).
Where does the data for Cl2 come from?
Cl2 data is cross-referenced from materials_project, aflow.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- aflow — Data from AFLOW. Cite: Curtarolo et al., Comp. Mater. Sci. 58, 218 (2012).
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