CsCuS4
CsCuS4 is a thermodynamically stable semiconducting sulfide compound composed of cesium, copper, and sulfur.

About CsCuS4
CsCuS4 is a ternary sulfide compound that exhibits semiconducting electronic behavior. As a thermodynamically stable phase located on the convex hull, it represents a robust structural arrangement of cesium, copper, and sulfur atoms.
This material is of interest to researchers investigating complex chalcogenides for optoelectronic or energy-related applications. Its stability suggests potential for synthesis and integration into functional devices where reliable semiconducting properties are required.
Key Properties
Cross-validated computational properties for CsCuS4, 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 CsCuS4. 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 CsCuS4, 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. |
|---|---|---|---|---|---|
| P212121 (No. 19) | orthorhombic | 1.78 | 0.0000 | -11.880 | 3.35 |
| P212121 (No. 19) | Orthorhombic | — | — | — | 3.22 |
| P212121 (No. 19) | Orthorhombic | — | — | — | 3.32 |
| P212121 (No. 19) | Orthorhombic | — | — | — | 3.28 |
| No. 0 | unknown | — | — | — | 1.69 |
Applications
Where CsCuS4 is used.
Frequently Asked Questions
Common questions about CsCuS4, answered from cross-validated data.
What is CsCuS4?
CsCuS4 is a thermodynamically stable semiconducting sulfide compound composed of cesium, copper, and sulfur.
What is CsCuS4 used for?
What is the band gap of CsCuS4?
Is CsCuS4 a metal, semiconductor, or insulator?
Is CsCuS4 thermodynamically stable?
What is the crystal structure of CsCuS4?
What is the density of CsCuS4?
How many polymorphs of CsCuS4 are known?
What elements does CsCuS4 contain?
Where does the data for CsCuS4 come from?
How It Compares
As a unique ternary sulfide, CsCuS4 serves as a distinct example of stable quaternary-like chalcogenide chemistry, providing a baseline for understanding how alkali metals and copper coordinate within sulfur-rich frameworks.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
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