K2S
Potassium sulfide · Dipotassium sulfide
Potassium sulfide is a stable, semiconducting inorganic compound used primarily as a chemical reagent and precursor in synthetic applications.
About Potassium sulfide
Potassium sulfide is a thermodynamically stable compound composed of potassium and sulfur. As a semiconducting material, it exhibits distinct electronic properties that make it a subject of interest in solid-state chemistry and materials research. Its presence on the convex hull indicates high structural stability under standard conditions. The compound is well-documented in structural databases, reflecting its significance in fundamental material studies. It serves as a precursor in various chemical reactions and is utilized in specialized industrial processes where sulfur-based reagents are required. Its reliable stability allows for consistent performance in laboratory settings, supporting its role as a foundational inorganic material.
Key Properties
Cross-validated computational properties for Potassium sulfide, 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 K2S. 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 K2S, 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. |
|---|---|---|---|---|---|
| — | — | 2.44 | 0.0000 | -1.163 | — |
| Fm-3m (No. 225) | cubic | 2.38 | 0.0000 | -1.222 | — |
| Fm-3m (No. 225) | cubic | 2.38 | 0.0000 | -1.222 | — |
| Fm-3m (No. 225) | cubic | 2.32 | 0.0000 | -7.938 | 1.80 |
| — | — | 2.57 | 0.0141 | -1.149 | — |
| — | — | 2.43 | 0.0298 | -1.133 | — |
| — | — | 0.00 | 0.0299 | -1.133 | — |
| — | — | 0.00 | 0.0300 | -1.133 | — |
| P63/mmc (No. 194) | hexagonal | 2.21 | 0.0320 | -1.190 | — |
| — | — | 2.37 | 0.0370 | -1.126 | — |
| P63/mmc (No. 194) | hexagonal | 2.40 | 0.0420 | -1.180 | — |
| — | — | 1.68 | 0.0825 | -1.080 | — |
Applications
Where Potassium sulfide is used.
Frequently Asked Questions
Common questions about Potassium sulfide, answered from cross-validated data.
What is K2S?
Potassium sulfide is a stable, semiconducting inorganic compound used primarily as a chemical reagent and precursor in synthetic applications.
What is K2S used for?
What is the band gap of K2S?
Is K2S a metal, semiconductor, or insulator?
Is K2S thermodynamically stable?
What is the crystal structure of K2S?
How many polymorphs of K2S are known?
What elements does K2S contain?
Where does the data for K2S come from?
How It Compares
As a primary sulfide of potassium, this compound serves as a fundamental reference point for alkali metal chalcogenides. It represents a stable, well-defined stoichiometry within the broader landscape of sulfur-containing inorganic materials, providing a baseline for understanding the electronic and structural behavior of related binary systems.
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)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
Analyze K2S in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 85 source databases.
Explore the Platform →