Ta2C
Ta2C has a DFT band gap of Metallic / not reported across 139 reported structures in 24 space groups; its reference structure is trigonal (P-3m1 (No. 164)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for Ta2C, 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.
0.000 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.
Stable
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
139
3 databases, 24 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of Ta2C. 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.
1.00 / 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.
0.000 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 Ta2C, 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. |
|---|---|---|---|---|---|
| — | — | 0.00 | 0.0000 | -0.606 | — |
| P-3m1 (No. 164) | trigonal | 0.00 | 0.0000 | -36.389 | 14.96 |
| P-3m1 (No. 164) | trigonal | 0.00 | 0.0000 | -0.620 | — |
| P6/mmm (No. 191) | hexagonal | 0.00 | 2.3226 | -34.067 | 13.25 |
| — | — | 0.00 | 2.8011 | 2.196 | — |
| — | — | 0.00 | 3.0294 | 2.424 | — |
| P1 (No. 1) | triclinic | — | — | — | 12.20 |
| P-1 (No. 2) | triclinic | — | — | — | 11.85 |
| P1 (No. 1) | triclinic | — | — | — | 13.09 |
| P1 (No. 1) | triclinic | — | — | — | 9.13 |
| P1 (No. 1) | triclinic | — | — | — | 9.98 |
| P1 (No. 1) | triclinic | — | — | — | 13.15 |
Reference
Frequently Asked Questions
Common questions about Ta2C, answered from cross-validated data.
What is the band gap of Ta2C?
The reported DFT structures of Ta2C 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 Ta2C 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 Ta2C thermodynamically stable?
Yes — Ta2C sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of Ta2C?
The reference structure of Ta2C is trigonal symmetry, space group P-3m1 (No. 164).
What is the density of Ta2C?
The computed density of the ground-state structure of Ta2C is 14.96 g/cm³.
How many polymorphs of Ta2C are known?
139 structures of Ta2C are reported across 3 databases, spanning 24 distinct space groups.
What elements does Ta2C contain?
Ta2C contains C and Ta (2 elements).
Where does the data for Ta2C come from?
Ta2C data is cross-referenced from oqmd, materials_project, jarvis, mpaloe.
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Related Compounds
Other Ultra-High-Temperature Ceramics in the database.
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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (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)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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