Si8
Si8 has a DFT band gap of 0.03–1.52 eV across 83 reported structures in 24 space groups; its lowest-energy polymorph is cubic (Fd-3m (No. 227)). Cross-validated across 5 computational databases.
Overview
Key Properties
Cross-validated computational properties for Si8, aggregated across 5 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.
0.03–1.52 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)
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
83
5 databases, 24 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for Si8, 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. |
|---|---|---|---|---|---|
| Fd-3m (No. 227) | cubic | 0.61 | 0.0000 | -8.774 | 2.31 |
| P63/mmc (No. 194) | hexagonal | 0.44 | 0.0136 | -8.760 | 2.32 |
| C2/m (No. 12) | monoclinic | 0.27 | 0.0822 | -8.692 | 2.23 |
| P63/mmc (No. 194) | hexagonal | 1.36 | 0.0844 | -8.689 | 2.01 |
| Pm-3n (No. 223) | cubic | 1.44 | 0.0918 | -8.682 | 2.03 |
| I-43m (No. 217) | cubic | 1.37 | 0.1075 | -8.666 | 2.11 |
| P6/mmm (No. 191) | hexagonal | 1.13 | 0.1105 | -8.663 | 2.01 |
| Cmcm (No. 63) | orthorhombic | 0.50 | 0.1105 | -8.663 | 2.15 |
| I4/mmm (No. 139) | tetragonal | 0.44 | 0.1166 | -8.657 | 2.19 |
| Pa-3 (No. 205) | cubic | 1.01 | 0.1212 | -8.653 | 1.97 |
| C2/c (No. 15) | monoclinic | 1.00 | 0.1289 | -8.645 | 2.04 |
| Cmcm (No. 63) | orthorhombic | 1.52 | 0.1291 | -8.645 | 2.01 |
Reference
Frequently Asked Questions
Common questions about Si8, answered from cross-validated data.
What is the band gap of Si8?
Si8 has a DFT-computed band gap of 0.03–1.52 eV across 83 reported structures.
More questions
Is Si8 a metal, semiconductor, or insulator?
With a band gap up to 1.52 eV it is a semiconductor.
Is Si8 thermodynamically stable?
Yes — Si8 sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of Si8?
The lowest-energy reported polymorph of Si8 is cubic symmetry, space group Fd-3m (No. 227).
What is the density of Si8?
The computed density of the ground-state structure of Si8 is 2.31 g/cm³.
How many polymorphs of Si8 are known?
83 structures of Si8 are reported across 5 databases, spanning 24 distinct space groups.
What elements does Si8 contain?
Si8 contains Si (1 element).
Where does the data for Si8 come from?
Si8 data is cross-referenced from materials_project.
Explore
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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