K2SO3
Potassium sulfite · Dipotassium sulfite
Potassium sulfite is an insulating, metastable sulfur-containing salt used primarily as a chemical reagent and preservative.
About Potassium sulfite
Potassium sulfite is a sulfur-based inorganic compound characterized by its wide-gap insulating electronic structure. As a metastable material, it exhibits distinct reactivity patterns that make it a significant subject for chemical synthesis and structural investigation. Its chemical behavior is driven by the sulfite anion, which plays a central role in its ability to participate in various redox reactions. The compound is frequently utilized in industrial processes where controlled sulfur delivery is required, leveraging its solubility and chemical stability profile. Its presence in multiple structural forms highlights the complexity of its crystalline arrangement, which is of ongoing interest to materials scientists studying alkali metal oxoanions.
Key Properties
Cross-validated computational properties for Potassium sulfite, 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.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of K2SO3. 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 K2SO3, 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 | 5.12 | 0.0400 | -1.869 | — |
| — | — | 5.02 | 0.0481 | -1.986 | — |
| — | — | 0.00 | 0.0575 | -1.977 | — |
| P-3m1 (No. 164) | trigonal | 4.92 | 0.0686 | -5.611 | 2.34 |
| Cc (No. 9) | monoclinic | 0.00 | 0.7715 | -4.908 | 1.75 |
| P-3m1 (No. 164) | trigonal | — | — | — | 2.34 |
| P-3m1 (No. 164) | trigonal | — | — | — | 2.45 |
| P-3m1 (No. 164) | trigonal | — | — | — | 2.38 |
Applications
Where Potassium sulfite is used.
Frequently Asked Questions
Common questions about Potassium sulfite, answered from cross-validated data.
What is K2SO3?
Potassium sulfite is an insulating, metastable sulfur-containing salt used primarily as a chemical reagent and preservative.
What is K2SO3 used for?
What is the band gap of K2SO3?
Is K2SO3 a metal, semiconductor, or insulator?
Is K2SO3 thermodynamically stable?
What is the crystal structure of K2SO3?
How many polymorphs of K2SO3 are known?
What elements does K2SO3 contain?
Where does the data for K2SO3 come from?
How It Compares
As a standalone member of its chemical class in this context, potassium sulfite serves as a fundamental reference point for understanding the behavior of alkali metal sulfites. Its metastable nature and insulating character distinguish it from more stable or conductive sulfur-containing salts, positioning it as a specialized reagent for applications requiring specific chemical reactivity rather than structural robustness.
Data sources & attribution
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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