FeNi

taenite · iron-nickel alloy

FeNi is a thermodynamically stable metallic alloy of iron and nickel that is widely studied for its structural properties and natural occurrence in meteorites.

FeNi
Crystal structure of FeNi (tetragonal, P4/mmm (No. 123))
Ground-state structure · Materials Project
Overview

About taenite

FeNi is a metallic alloy composed of iron and nickel that exhibits robust thermodynamic stability. As a material that sits directly on the convex hull, it represents a highly favorable structural state for these two transition metals, reflecting a deep-seated chemical compatibility that facilitates its formation in various environments.

Beyond its fundamental scientific interest, this compound is a subject of extensive structural investigation, with numerous reported configurations across major databases. Its metallic nature and stability make it a cornerstone for understanding phase transitions in planetary science and advanced alloy design.

At a glance

Key Properties

Cross-validated computational properties for taenite, aggregated across 4 databases.

Band Gap

Metallic / not reported

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

47
4 databases, 14 space groups
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of FeNi. Tight agreement means computed properties can be trusted without re-running calculations.

Agreement Score

1.00 / 1.00
Trust tier: medium

Hull Spread

0.000 eV
EAH spread across sources

Sources Compared

2
jarvis, materials_project

Space Group Consensus

All match
Crystallography

Reported Structures

Lowest-energy structures reported for FeNi, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
P4/mmm (No. 123)tetragonal0.000.0000-7.1928.54
R-3m (No. 166)trigonal0.000.0686-7.1248.40
Cmmm (No. 65)orthorhombic0.000.0832-7.1098.46
P21 (No. 4)Monoclinic8.38
P4/mmm (No. 123)Tetragonal8.57
P21/m (No. 11)Monoclinic5.08
P21/m (No. 11)Monoclinic5.16
Cm (No. 8)Monoclinic3.97
Cmcm (No. 63)Orthorhombic4.03
P4/mmm (No. 123)
P21 (No. 4)Monoclinic5.27
Cm (No. 8)Monoclinic5.16
Uses

Applications

Where taenite is used.

metallurgical researchplanetary sciencealloy developmentmagnetic material studies
Reference

Frequently Asked Questions

Common questions about taenite, answered from cross-validated data.

What is FeNi?

FeNi is a thermodynamically stable metallic alloy of iron and nickel that is widely studied for its structural properties and natural occurrence in meteorites.

More questions
What is FeNi used for?
taenite (FeNi) is used in metallurgical research, planetary science, alloy development, and magnetic material studies.
What is the band gap of FeNi?
taenite (FeNi) is computed to be metallic (no band gap) in the reported DFT structures.
Is FeNi a metal, semiconductor, or insulator?
Computed band structures report no gap, so it is metallic.
Is FeNi thermodynamically stable?
Yes — taenite (FeNi) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of FeNi?
The lowest-energy reported polymorph of taenite (FeNi) is tetragonal symmetry, space group P4/mmm (No. 123).
What is the density of FeNi?
The computed density of the ground-state structure of taenite (FeNi) is 8.54 g/cm³.
How many polymorphs of FeNi are known?
47 structures of FeNi are reported across 4 databases, spanning 14 distinct space groups.
What elements does FeNi contain?
taenite (FeNi) contains Fe and Ni (2 elements).
Where does the data for FeNi come from?
FeNi data is cross-referenced from materials_project, mpaloe, jarvis, cod.
Comparison

How It Compares

As a foundational binary metallic system, FeNi serves as a primary reference point for the study of iron-nickel intermetallics and their diverse structural behaviors under varying conditions.

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).
  • cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).

Analyze FeNi in the Lattice Graph platform

Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.

Explore the Platform →