NbC
NbC has a DFT band gap of Metallic / not reported across 306 reported structures in 39 space groups; its reference structure is cubic (Fm-3m (No. 225)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for NbC, 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.
Metallic / not reported
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.
0.015 eV/atom
Best (lowest) across sources
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.
Near Hull
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
306
3 databases, 39 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of NbC. 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.
0.89 / 1.00
Trust tier: high
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.027 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
3
jarvis, materials_project, oqmd
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for NbC, 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. |
|---|---|---|---|---|---|
| Fm-3m (No. 225) | cubic | 0.00 | 0.0145 | -0.528 | — |
| Fm-3m (No. 225) | cubic | 0.00 | 0.0298 | -17.876 | 7.61 |
| — | — | 0.00 | 0.0411 | -0.467 | — |
| — | — | 0.00 | 0.0413 | -0.467 | — |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.1217 | -0.420 | — |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.1457 | -17.761 | 7.62 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.1543 | -0.388 | — |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.1686 | -17.738 | 6.52 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.3726 | -0.169 | — |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.4102 | -17.496 | 7.24 |
| — | — | 0.00 | 0.4422 | -0.066 | — |
| F-43m (No. 216) | cubic | 0.00 | 0.5629 | 0.021 | — |
Intellectual Property
Patent Landscape
1 patent reference NbC or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 6855216 | Method of processing and heat-treating NbC-added Fe-Mn-Si-based shape memory alloy | — | — |
Reference
Frequently Asked Questions
Common questions about NbC, answered from cross-validated data.
What is the band gap of NbC?
The reported DFT structures of NbC show no band gap. Standard DFT often misses gaps (especially in transition-metal oxides), so this is not proof the real material is a metal.
More questions
Is NbC a metal, semiconductor, or insulator?
DFT calculations predict no band gap. Standard DFT can miss gaps, so measurements are needed to confirm metallic behavior.
Is NbC thermodynamically stable?
NbC has a lowest energy above hull of 0.015 eV/atom (near hull).
What is the crystal structure of NbC?
The reference structure of NbC is cubic symmetry, space group Fm-3m (No. 225).
How many polymorphs of NbC are known?
306 structures of NbC are reported across 3 databases, spanning 39 distinct space groups.
What elements does NbC contain?
NbC contains C and Nb (2 elements).
Where does the data for NbC come from?
NbC data is cross-referenced from jarvis, materials_project, oqmd, mpaloe.
Explore
Related Compounds
Other Ultra-High-Temperature Ceramics in the database.
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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- 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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
Analyze NbC in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 85 source databases.
Explore the Platform →