Cs
Cesium · Caesium
Cesium is a highly reactive, soft alkali metal that exhibits semiconducting properties and is widely utilized in precision atomic and optical applications.
About Cesium
Cesium is a distinctive alkali metal known for its extreme reactivity and unique electronic properties. As a thermodynamically stable element, it occupies a significant position in fundamental materials science, often studied for its behavior under various structural configurations.
Its semiconducting characteristics make it a subject of interest in specialized electronic and optical research. Due to its high sensitivity to light and low ionization threshold, it serves as a critical component in high-precision instrumentation and vacuum-based technologies.
Key Properties
Cross-validated computational properties for Cesium, aggregated across 3 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.
Reported Structures
Lowest-energy structures reported for Cs, 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. |
|---|---|---|---|---|---|
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0000 | -25.108 | 1.80 |
| Fm-3m (No. 225) | cubic | 0.00 | 0.0092 | -25.099 | 1.79 |
| I-43m (No. 217) | cubic | 0.14 | 0.0126 | -25.096 | 1.79 |
| P4132 (No. 213) | cubic | 0.00 | 0.0131 | -25.095 | 1.75 |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0172 | -25.091 | 1.80 |
| Im-3m (No. 229) | cubic | 0.00 | 0.0193 | -25.089 | 1.80 |
| I4/mmm (No. 139) | tetragonal | 0.00 | 0.0196 | -25.089 | 1.78 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.0198 | -25.089 | 1.78 |
| P63/mmc (No. 194) | hexagonal | 0.00 | 0.0199 | -25.089 | 1.78 |
| Pbcm (No. 57) | orthorhombic | 0.00 | 0.0243 | -25.084 | 1.77 |
| Pbcm (No. 57) | orthorhombic | 0.00 | 0.0244 | -25.084 | 1.77 |
| P42/mbc (No. 135) | tetragonal | 0.00 | 0.0275 | -25.081 | 1.78 |
Applications
Where Cesium is used.
Frequently Asked Questions
Common questions about Cesium, answered from cross-validated data.
What is Cs?
Cesium is a highly reactive, soft alkali metal that exhibits semiconducting properties and is widely utilized in precision atomic and optical applications.
What is Cs used for?
What is the band gap of Cs?
Is Cs a metal, semiconductor, or insulator?
Is Cs thermodynamically stable?
What is the crystal structure of Cs?
What is the density of Cs?
How many polymorphs of Cs are known?
What elements does Cs contain?
Where does the data for Cs come from?
How It Compares
As a singular elemental material, Cesium stands as a foundational reference point for the study of alkali metals, providing essential data for understanding the periodic trends and structural diversity inherent in its group.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
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