C9Si9
C9Si9 has a DFT band gap of 1.37–2.35 eV across 44 reported structures in 7 space groups; its lowest-energy polymorph is trigonal (R3m (No. 160)). Cross-validated across 4 computational databases.
At a glance
Key Properties
Cross-validated computational properties for C9Si9, 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.
1.37–2.35 eV
Range across DFT structures
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.
On hull (stable)
2 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
44
4 databases, 7 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for C9Si9, 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. |
|---|---|---|---|---|---|
| R3m (No. 160) | trigonal | 1.84 | 0.0000 | -9.666 | 3.23 |
| P63mc (No. 186) | hexagonal | 2.02 | 0.0000 | -9.666 | 3.23 |
| R3m (No. 160) | trigonal | 1.85 | 0.0000 | -9.666 | 3.23 |
| P3m1 (No. 156) | trigonal | 1.81 | 0.0000 | -9.666 | 3.23 |
| R3m (No. 160) | trigonal | 1.97 | 0.0000 | -9.666 | 3.23 |
| P3m1 (No. 156) | trigonal | 1.69 | 0.0000 | -9.666 | 3.23 |
| P3m1 (No. 156) | trigonal | 1.94 | 0.0001 | -9.666 | 3.23 |
| P63mc (No. 186) | hexagonal | 1.97 | 0.0001 | -9.666 | 3.23 |
| P63mc (No. 186) | hexagonal | 1.78 | 0.0001 | -9.666 | 3.23 |
| R3m (No. 160) | trigonal | 1.95 | 0.0001 | -9.666 | 3.23 |
| P3m1 (No. 156) | trigonal | 2.01 | 0.0001 | -9.666 | 3.23 |
| P3m1 (No. 156) | trigonal | 1.97 | 0.0001 | -9.666 | 3.23 |
Reference
Frequently Asked Questions
Common questions about C9Si9, answered from cross-validated data.
What is the band gap of C9Si9?
C9Si9 has a DFT-computed band gap of 1.37–2.35 eV across 44 reported structures.
More questions
Is C9Si9 a metal, semiconductor, or insulator?
With a band gap up to 2.35 eV it is a semiconductor.
Is C9Si9 thermodynamically stable?
Yes — C9Si9 sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of C9Si9?
The lowest-energy reported polymorph of C9Si9 is trigonal symmetry, space group R3m (No. 160).
What is the density of C9Si9?
The computed density of the ground-state structure of C9Si9 is 3.23 g/cm³.
How many polymorphs of C9Si9 are known?
44 structures of C9Si9 are reported across 4 databases, spanning 7 distinct space groups.
What elements does C9Si9 contain?
C9Si9 contains C and Si (2 elements).
Where does the data for C9Si9 come from?
C9Si9 data is cross-referenced from materials_project.
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Related Compounds
Other Silicon Anode Materials in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
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