Jul 28

Fe16N2 (α''-Fe16N2, I4/mmm) benchmark CIF

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Overview

3030

Structure

Formula: Fe₈N
Space group: I4/mmm (139)
Crystal system: Tetragonal
Atoms per cell: 18

Structure

Formula: Fe₈N
Space group: I4/mmm (139)
Crystal system: Tetragonal
Atoms per cell: 18

Lattice a, b, c

5.720 Å, 5.720 Å, 6.290 Å

Angles α, β, γ

90.00°, 90.00°, 90.00°

Volume

205.80 Å³

Density

7.44 g/cm³

Attribution

Connections

4

Derived assets

Fe16N2 (α''-Fe16N2, I4/mmm) benchmark CIF - relaxed
.cif
Cell + Ionic relaxation with Orb v3 conservative inf MPA; 0.03 eV/Å threshold; final energy = -152.0602 eV; energy change = -31.0418 eV; symmetry: I4/mmm → I4/mmm

Included in datasets

MLIP Failure Mode Benchmark Dataset
Community benchmark dataset cataloging where universal machine-learned interatomic potentials (MLIPs) break. Contains 22 cases across 2 material families (spinels, perovskites) tested against 3 MLIP architectures (Orb v3, CHGNet, MACE-MP). NOTE 2026-07-24: All 9 spinel cases RETRACTED/INVALIDATED — original input CIFs had overlapping oxygen atoms (48 pairs at ~0.32 A). Corrected Co3O4 preserves Fd-3m under Orb v3 (verified). Other 4 spinels untested with corrected CIFs. CHGNet/MACE cross-architecture results also from flawed CIFs, retracted. Perovskite findings and ALIGNN composition-based predictions remain valid. CC-BY 4.0.

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Recent runs

Exchange couplings (TB2J)timed out
Exchange couplings (TB2J)error
Exchange couplings (TB2J)error

α''-Fe16N2 benchmark CIF for TB2J calibration ladder. Space group I4/mmm (#139), a=5.72, c=6.29 Å. Fe at 4d, 4e (z=0.30), 8h (x=0.20); N at 2b. Z=2, 18 atoms. Experimental lattice from Jack (1951). Supply-chain-optimal RE-free magnet candidate (HHI 1373, $0.42/kg). Next TB2J anchor after bcc Fe.

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30

Stats

Size: 1.55 KB
Type: .cif file
Downloads: 0

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Connections

4

Derived assets

Fe16N2 (α''-Fe16N2, I4/mmm) benchmark CIF - relaxed
.cif
Cell + Ionic relaxation with Orb v3 conservative inf MPA; 0.03 eV/Å threshold; final energy = -152.0602 eV; energy change = -31.0418 eV; symmetry: I4/mmm → I4/mmm

Included in datasets

MLIP Failure Mode Benchmark Dataset
Community benchmark dataset cataloging where universal machine-learned interatomic potentials (MLIPs) break. Contains 22 cases across 2 material families (spinels, perovskites) tested against 3 MLIP architectures (Orb v3, CHGNet, MACE-MP). NOTE 2026-07-24: All 9 spinel cases RETRACTED/INVALIDATED — original input CIFs had overlapping oxygen atoms (48 pairs at ~0.32 A). Corrected Co3O4 preserves Fd-3m under Orb v3 (verified). Other 4 spinels untested with corrected CIFs. CHGNet/MACE cross-architecture results also from flawed CIFs, retracted. Perovskite findings and ALIGNN composition-based predictions remain valid. CC-BY 4.0.