FeF2
Iron(II) fluoride · Ferrous fluoride
Iron(II) fluoride is an inorganic compound that typically appears as a crystalline solid. It is primarily utilized in chemical synthesis and as a catalyst in various industrial processes.
FFe
Overview
Key Properties
Cross-validated computational properties for Iron(II) fluoride, 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.
1.69 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)
2 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
165
3 databases, 28 space groups
Crystallography
Reported Structures
Lowest-energy structures reported for FeF2, 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. |
|---|---|---|---|---|---|
| P42/mnm (No. 136) | tetragonal | 1.69 | 0.0000 | -6.690 | 4.32 |
| Cm (No. 8) | Monoclinic | — | — | — | 4.70 |
| Cm (No. 8) | Monoclinic | — | — | — | 6.54 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.10 |
| Cm (No. 8) | Monoclinic | — | — | — | 5.46 |
| P3m1 (No. 156) | Trigonal | — | — | — | 3.78 |
| P3m1 (No. 156) | Trigonal | — | — | — | 4.16 |
| P3m1 (No. 156) | Trigonal | — | — | — | 3.84 |
| R-3m (No. 166) | Trigonal | — | — | — | 6.19 |
| C2/m (No. 12) | Monoclinic | — | — | — | 3.95 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.30 |
| P42/mnm (No. 136) | — | — | — | — | — |
Uses
Applications
Where Iron(II) fluoride is used.
Chemical synthesisCatalysisLaboratory reagent
Reference
Frequently Asked Questions
Common questions about Iron(II) fluoride, answered from cross-validated data.
What is FeF2?
Iron(II) fluoride is an inorganic compound that typically appears as a crystalline solid. It is primarily utilized in chemical synthesis and as a catalyst in various industrial processes.
More questions
What is FeF2 used for?
Iron(II) fluoride (FeF2) is used in chemical synthesis, catalysis, and laboratory reagent.
What is the band gap of FeF2?
Iron(II) fluoride (FeF2) has a DFT-computed band gap of 1.69 eV across 165 reported structures.
Is FeF2 a metal, semiconductor, or insulator?
With a band gap up to 1.69 eV it is a semiconductor.
Is FeF2 thermodynamically stable?
Yes — Iron(II) fluoride (FeF2) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of FeF2?
The lowest-energy reported polymorph of Iron(II) fluoride (FeF2) is tetragonal symmetry, space group P42/mnm (No. 136).
What is the density of FeF2?
The computed density of the ground-state structure of Iron(II) fluoride (FeF2) is 4.32 g/cm³.
How many polymorphs of FeF2 are known?
165 structures of FeF2 are reported across 3 databases, spanning 28 distinct space groups.
What elements does FeF2 contain?
Iron(II) fluoride (FeF2) contains F and Fe (2 elements).
Where does the data for FeF2 come from?
FeF2 data is cross-referenced from materials_project, mpaloe, jarvis.
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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