Ni2S
Ni2S is a metallic nickel sulfide compound known for its structural complexity and metastable nature.
About Ni2S
Ni2S is a metallic nickel sulfide characterized by its conductive electronic nature. As a material that resides above the thermodynamic hull, it is considered a metastable phase that presents unique challenges for synthesis and long-term structural retention.
Its significance lies in its complex structural landscape, with numerous reported configurations across various databases. Researchers study this compound to better understand the phase stability and bonding characteristics within the nickel-sulfur binary system.
Key Properties
Cross-validated computational properties for Ni2S, aggregated across 4 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 Ni2S. 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 Ni2S, 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. |
|---|---|---|---|---|---|
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.3772 | -5.332 | 7.19 |
| P1 (No. 1) | Triclinic | — | — | — | 6.01 |
| P-6m2 (No. 187) | Hexagonal | — | — | — | 6.25 |
| P-6m2 (No. 187) | Hexagonal | — | — | — | 6.41 |
| P3m1 (No. 156) | Trigonal | — | — | — | 5.75 |
| I4/mmm (No. 139) | — | — | — | — | — |
| C2 (No. 5) | Monoclinic | — | — | — | 6.20 |
| C2 (No. 5) | Monoclinic | — | — | — | 4.49 |
| P1 (No. 1) | Triclinic | — | — | — | 7.48 |
| C2 (No. 5) | Monoclinic | — | — | — | 6.67 |
| P1 (No. 1) | Triclinic | — | — | — | 6.69 |
| P-1 (No. 2) | Triclinic | — | — | — | 5.41 |
Applications
Where Ni2S is used.
Frequently Asked Questions
Common questions about Ni2S, answered from cross-validated data.
What is Ni2S?
Ni2S is a metallic nickel sulfide compound known for its structural complexity and metastable nature.
What is Ni2S used for?
What is the band gap of Ni2S?
Is Ni2S a metal, semiconductor, or insulator?
Is Ni2S thermodynamically stable?
What is the crystal structure of Ni2S?
What is the density of Ni2S?
How many polymorphs of Ni2S are known?
What elements does Ni2S contain?
Where does the data for Ni2S come from?
How It Compares
As a member of the nickel-sulfur binary system, Ni2S represents a distinct stoichiometry that deviates from more common, stable sulfide phases. Its metallic character and metastable status distinguish it from more robust, naturally occurring nickel sulfides, positioning it as a specialized subject for fundamental studies in non-equilibrium materials science.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
Analyze Ni2S in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.
Explore the Platform →