Ca2Si
Ca2Si is a thermodynamically stable semiconducting silicide compound widely researched for its potential as a high-performance anode material in advanced battery technologies.
About Ca2Si
Ca2Si is a semiconducting intermetallic compound that occupies a stable position on the convex hull, indicating robust thermodynamic favorability. As a member of the silicide family, it serves as a critical subject of study for material scientists investigating structural transformations in energy storage systems.
Its structural complexity is evidenced by a significant number of reported configurations across major materials databases. This diversity in atomic arrangement makes it a compelling candidate for researchers aiming to tune the electrochemical properties of silicon-based anodes for improved battery performance.
Key Properties
Cross-validated computational properties for Ca2Si, 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.
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 Ca2Si. 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 Ca2Si, 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. |
|---|---|---|---|---|---|
| Fm-3m (No. 225) | cubic | 0.55 | 0.0000 | -8.151 | 1.95 |
| — | — | 0.38 | 0.0000 | -0.472 | — |
| Pnma (No. 62) | orthorhombic | 0.29 | 0.0000 | -0.552 | — |
| Pnma (No. 62) | orthorhombic | 0.29 | 0.0011 | -8.150 | 2.17 |
| — | — | 0.71 | 0.0150 | -0.457 | — |
| — | — | 0.71 | 0.0150 | -0.457 | — |
| — | — | 0.61 | 0.0150 | -0.457 | — |
| Fm-3m (No. 225) | cubic | 0.64 | 0.0188 | -0.534 | — |
| — | — | 0.00 | 0.0366 | -0.435 | — |
| — | — | 0.00 | 0.2208 | -0.251 | — |
| — | — | 0.00 | 0.2571 | -0.214 | — |
| — | — | 0.00 | 0.4420 | -0.030 | — |
Applications
Where Ca2Si is used.
Frequently Asked Questions
Common questions about Ca2Si, answered from cross-validated data.
What is Ca2Si?
Ca2Si is a thermodynamically stable semiconducting silicide compound widely researched for its potential as a high-performance anode material in advanced battery technologies.
What is Ca2Si used for?
What is the band gap of Ca2Si?
Is Ca2Si a metal, semiconductor, or insulator?
Is Ca2Si thermodynamically stable?
What is the crystal structure of Ca2Si?
How many polymorphs of Ca2Si are known?
What elements does Ca2Si contain?
Where does the data for Ca2Si come from?
How It Compares
Within the silicon anode materials class.
Within the broader class of silicon anode materials, Ca2Si distinguishes itself through its specific alkaline-earth stoichiometry compared to the transition metal silicides like FeSi or MoSi2. While it shares a silicide foundation with Mg2Si, its unique calcium-based framework offers distinct mechanical and electronic characteristics that differentiate it from both simple elemental silicon and more complex binary systems like BaSi2.
Related Compounds
Other Silicon Anode Materials 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)
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
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