Al2O9Si2
Al2O9Si2 is a semiconducting aluminosilicate framework that exists as a metastable phase within the broader family of aluminum-silicon-oxygen materials.
About Al2O9Si2
Al2O9Si2 is a complex aluminosilicate characterized by its semiconducting electronic behavior. As a member of the aluminosilicate and zeolite framework family, it represents a specific structural arrangement of aluminum, silicon, and oxygen atoms that is of interest for fundamental materials research.
While this compound exhibits a unique structural configuration, it is classified as thermodynamically unstable relative to the ground state. Its existence in reported structural databases highlights its role in the study of metastable phases within the vast landscape of silicate materials.
Key Properties
Cross-validated computational properties for Al2O9Si2, aggregated across 2 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 Al2O9Si2. Tight agreement means computed properties can be trusted without re-running calculations.
Only 1 independent DFT source (materials_project) reports a hull energy for Al2O9Si2, so cross-source agreement can't be assessed yet.
Reported Structures
Lowest-energy structures reported for Al2O9Si2, 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. |
|---|---|---|---|---|---|
| P1 (No. 1) | triclinic | 0.00 | 0.3167 | -7.353 | 2.40 |
| Cc (No. 9) | monoclinic | 0.32 | 0.3169 | -7.353 | 2.36 |
| Cc (No. 9) | monoclinic | 0.23 | 0.3176 | -7.352 | 2.36 |
| Cc (No. 9) | monoclinic | 0.00 | 0.3184 | -7.351 | 2.40 |
| Cc (No. 9) | monoclinic | 0.24 | 0.3185 | -7.351 | 2.40 |
| P1 (No. 1) | triclinic | 0.03 | 0.5887 | -7.081 | 2.29 |
| Cc (No. 9) | monoclinic | — | — | — | 2.56 |
| Cc (No. 9) | monoclinic | — | — | — | 2.57 |
| Cc (No. 9) | monoclinic | — | — | — | 2.56 |
Frequently Asked Questions
Common questions about Al2O9Si2, answered from cross-validated data.
What is Al2O9Si2?
Al2O9Si2 is a semiconducting aluminosilicate framework that exists as a metastable phase within the broader family of aluminum-silicon-oxygen materials.
What is the band gap of Al2O9Si2?
Is Al2O9Si2 a metal, semiconductor, or insulator?
Is Al2O9Si2 thermodynamically stable?
What is the crystal structure of Al2O9Si2?
What is the density of Al2O9Si2?
How many polymorphs of Al2O9Si2 are known?
What elements does Al2O9Si2 contain?
Where does the data for Al2O9Si2 come from?
How It Compares
Within the aluminosilicates and zeolite frameworks class.
Compared to more common and thermodynamically stable aluminosilicates like Al2SiO5 or the framework-rich NaAlSi3O8, Al2O9Si2 occupies a more precarious position on the energy landscape. While siblings like KAlSiO4 and LiAlSiO4 are well-known for their robust structural frameworks, this compound is distinguished by its placement above the hull, suggesting that it represents a less common or transient structural possibility within the aluminosilicate class.
Related Compounds
Other Aluminosilicates and Zeolite Frameworks in the database.
Data sources & attribution
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
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