MgB2
MgB2 has a DFT band gap of 0.20 eV across 58 reported structures in 16 space groups; its reference structure is hexagonal (P6/mmm (No. 191)). Cross-validated across 3 computational databases.
At a glance
Key Properties
Cross-validated computational properties for MgB2, 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.
0.20 eV
Range across DFT structures · ground state: metal
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.
Stable
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
58
3 databases, 16 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of MgB2. 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.
1.00 / 1.00
Trust tier: high
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.000 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
3
jarvis, materials_project, oqmd
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for MgB2, 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. |
|---|---|---|---|---|---|
| P6/mmm (No. 191) | hexagonal | 0.00 | 0.0000 | -0.194 | — |
| — | — | 0.00 | 0.0000 | -0.140 | — |
| P6/mmm (No. 191) | hexagonal | 0.00 | 0.0000 | -0.194 | — |
| P6/mmm (No. 191) | hexagonal | 0.00 | 0.0000 | -6.463 | 2.67 |
| — | — | 0.00 | 0.8844 | 0.744 | — |
| P6/mmm (No. 191) | hexagonal | 0.00 | 1.3888 | 1.195 | — |
| — | — | 0.00 | 1.4436 | 1.304 | — |
| — | — | 0.20 | 3.1112 | 2.971 | — |
| P1 (No. 1) | triclinic | — | — | — | 1.73 |
| C2 (No. 5) | monoclinic | — | — | — | 1.98 |
| P1 (No. 1) | triclinic | — | — | — | 1.28 |
| P1 (No. 1) | triclinic | — | — | — | 1.18 |
Synthesis
Synthesis Routes
Literature-extracted synthesis procedures targeting MgB2.
Sol Gel
Procedure available · ceder_sol_gel
Solid State
Procedure available · ceder_solid_state
Solid State
Procedure available · ceder_solid_state
Solid State
Procedure available · ceder_solid_state
Solid State
Procedure available · ceder_solid_state
Solid State
Procedure available · ceder_solid_state
Intellectual Property
Patent Landscape
14 patents reference MgB2 or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 7337527 | Method including a heat treatment of manufacturing superconducting wires based on MgB2 | — | — |
| 9224937 | Precursor of MgB2 superconducting wire, and method for producing the same | — | — |
| 8709961 | Method for superconducting connection between MgB2 superconducting wires via a MgB2 matrix made from a boron p | — | — |
| 8420558 | Superconducting connection between MgB2 superconducting wires via a compressed element made from HTS powder | — | — |
| 10128024 | MgB2-based superconducting wire for a liquid hydrogen level sensor, a liquid hydrogen level sensor, and a liqu | — | — |
| 6957480 | Method for the production of superconductive wires based on hollow filaments made of MgB2 | — | — |
| 6953770 | MgB2—based superconductor with high critical current density, and method for manufacturing the same | — | — |
| 11551832 | Superconductor wire based on MgB2 core with AI based sheath and method of its production | — | — |
| 10431823 | Method for manufacturing base material powder having carbon nano-coating layer, method for manufacturing MgB2 | — | — |
| 7541313 | Method for producing MgB2 superconductor | — | — |
Reference
Frequently Asked Questions
Common questions about MgB2, answered from cross-validated data.
What is the band gap of MgB2?
MgB2 has a DFT-computed band gap of 0.20 eV across 58 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
More questions
Is MgB2 a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 0.20 eV (a semiconductor). Measured gaps are typically larger.
Is MgB2 thermodynamically stable?
Yes — MgB2 sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of MgB2?
The reference structure of MgB2 is hexagonal symmetry, space group P6/mmm (No. 191).
How many polymorphs of MgB2 are known?
58 structures of MgB2 are reported across 3 databases, spanning 16 distinct space groups.
How is MgB2 synthesized?
Literature-reported routes for MgB2 include sol gel, solid state (10 procedures documented).
What elements does MgB2 contain?
MgB2 contains B and Mg (2 elements).
Where does the data for MgB2 come from?
MgB2 data is cross-referenced from jarvis, oqmd, materials_project, mpaloe, cod.
Reading
Related Research
Explore
Related Compounds
Other Transition-Metal Borides in the database.
Data sources & attribution
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- 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)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
- 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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