C
Diamond · Carbon
Diamond is a highly stable, wide-band-gap insulating form of carbon prized for its extreme hardness and optical clarity.
About Diamond
Diamond is a naturally occurring allotrope of carbon that represents one of the most stable configurations of the element. Its unique crystalline structure grants it exceptional physical properties, making it a benchmark for material strength and thermal conductivity in high-performance engineering.
As a wide-band-gap insulator, this material is highly valued in advanced electronics and optics. Its thermodynamic stability ensures that it remains a robust choice for demanding industrial environments where durability and chemical inertness are paramount.
Key Properties
Cross-validated computational properties for Diamond, aggregated across 6 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 C. 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 C, 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 | 4.90 | 0.0000 | 0.112 | — |
| R-3m (No. 166) | trigonal | 4.80 | 0.0000 | 0.110 | — |
| P63/mmc (No. 194) | hexagonal | 4.74 | 0.0000 | 0.109 | — |
| R-3m (No. 166) | trigonal | 4.71 | 0.0000 | 0.107 | — |
| P63/mmc (No. 194) | hexagonal | 4.70 | 0.0000 | 0.107 | — |
| Fd-3m (No. 227) | cubic | 4.46 | 0.0000 | 0.102 | — |
| Fd-3m (No. 227) | cubic | 4.46 | 0.0000 | 0.102 | — |
| Pnma (No. 62) | orthorhombic | 4.44 | 0.0000 | 0.264 | — |
| P63/mmc (No. 194) | hexagonal | 3.76 | 0.0000 | 0.129 | — |
| P63/mmc (No. 194) | hexagonal | 3.76 | 0.0000 | 0.129 | — |
| Cmmm (No. 65) | orthorhombic | 3.54 | 0.0000 | 0.238 | — |
| Im-3m (No. 229) | cubic | 3.09 | 0.0000 | 0.782 | — |
Applications
Where Diamond is used.
Frequently Asked Questions
Common questions about Diamond, answered from cross-validated data.
What is C?
Diamond is a highly stable, wide-band-gap insulating form of carbon prized for its extreme hardness and optical clarity.
What is C used for?
What is the band gap of C?
Is C a metal, semiconductor, or insulator?
Is C thermodynamically stable?
What is the crystal structure of C?
How many polymorphs of C are known?
What elements does C contain?
Where does the data for C come from?
How It Compares
As a singular, highly distinct form of carbon, diamond stands as the primary reference point for carbon-based materials science, defining the upper limits of hardness and insulating capability within the broader family of elemental structures.
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)
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