K2S

Potassium sulfide · Dipotassium sulfide

Potassium sulfide is a stable, semiconducting inorganic compound used primarily as a chemical reagent and precursor in synthetic applications.

KS
Crystal structure of K2S (cubic, Fm-3m (No. 225))
Ground-state structure · Materials Project
Overview

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.

At a glance

Key Properties

Cross-validated computational properties for Potassium sulfide, aggregated across 3 databases.

Band Gap

2.06–2.32 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

15
3 databases, 3 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for K2S, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
Fm-3m (No. 225)cubic2.320.0000-7.9381.80
P63/mmc (No. 194)hexagonal2.060.0873-7.8512.06
Fm-3m (No. 225)
P63/mmc (No. 194)
Fm-3m (No. 225)Cubic1.83
P63/mmc (No. 194)
Fm-3m (No. 225)Cubic1.76
P63/mmc (No. 194)Hexagonal2.12
Fm-3m (No. 225)
Fm-3m (No. 225)Cubic1.78
P63/mmc (No. 194)Hexagonal2.06
P63/mmc (No. 194)Hexagonal2.10
Uses

Applications

Where Potassium sulfide is used.

Chemical synthesisLaboratory reagentPrecursor for inorganic materials
Reference

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.

More questions
What is K2S used for?
Potassium sulfide (K2S) is used in chemical synthesis, laboratory reagent, and precursor for inorganic materials.
What is the band gap of K2S?
Potassium sulfide (K2S) has a DFT-computed band gap of 2.06–2.32 eV across 15 reported structures.
Is K2S a metal, semiconductor, or insulator?
With a band gap up to 2.32 eV it is a semiconductor.
Is K2S thermodynamically stable?
Yes — Potassium sulfide (K2S) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of K2S?
The lowest-energy reported polymorph of Potassium sulfide (K2S) is cubic symmetry, space group Fm-3m (No. 225).
What is the density of K2S?
The computed density of the ground-state structure of Potassium sulfide (K2S) is 1.80 g/cm³.
How many polymorphs of K2S are known?
15 structures of K2S are reported across 3 databases, spanning 3 distinct space groups.
What elements does K2S contain?
Potassium sulfide (K2S) contains K and S (2 elements).
Where does the data for K2S come from?
K2S data is cross-referenced from materials_project, jarvis, mpaloe.
Comparison

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
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
  • mpaloe — Data from mpaloe.

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