Al2C2Ta4
Al2C2Ta4 has a DFT band gap of Metallic / not reported across 7 reported structures in 2 space groups; its lowest-energy polymorph is hexagonal (P63/mmc (No. 194)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for Al2C2Ta4, 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.
0.006 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 (likely stable)
1 DFT source
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
7
3 databases, 2 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for Al2C2Ta4, 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. |
|---|---|---|---|---|---|
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.0059 | -29.046 | 11.63 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.5642 | -28.488 | 10.39 |
| P63/mmc (No. 194) | — | — | — | — | — |
| P63/mmc (No. 194) | — | — | — | — | — |
| No. 0 | unknown | — | — | — | 4.21 |
| P63/mmc (No. 194) | — | — | — | — | — |
| No. 0 | unknown | — | — | — | 4.17 |
Reference
Frequently Asked Questions
Common questions about Al2C2Ta4, answered from cross-validated data.
What is the band gap of Al2C2Ta4?
Al2C2Ta4 is computed to be metallic (no band gap) in the reported DFT structures.
More questions
Is Al2C2Ta4 a metal, semiconductor, or insulator?
Computed band structures report no gap, so it is metallic.
Is Al2C2Ta4 thermodynamically stable?
Al2C2Ta4 has a lowest energy above hull of 0.006 eV/atom (near hull (likely stable)).
What is the crystal structure of Al2C2Ta4?
The lowest-energy reported polymorph of Al2C2Ta4 is hexagonal symmetry, space group P63/mmc (No. 194).
What is the density of Al2C2Ta4?
The computed density of the ground-state structure of Al2C2Ta4 is 11.63 g/cm³.
How many polymorphs of Al2C2Ta4 are known?
7 structures of Al2C2Ta4 are reported across 3 databases, spanning 2 distinct space groups.
What elements does Al2C2Ta4 contain?
Al2C2Ta4 contains Al, C, and Ta (3 elements).
Where does the data for Al2C2Ta4 come from?
Al2C2Ta4 data is cross-referenced from materials_project, aflow, cod.
Explore
Related Compounds
Other MAX Phases in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- aflow — Data from AFLOW. Cite: Curtarolo et al., Comp. Mater. Sci. 58, 218 (2012).
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
Analyze Al2C2Ta4 in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.
Explore the Platform →