---
title: "Fe16N2 (α''-Fe16N2, I4/mmm) benchmark CIF"
description: "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."
url: "https://ouro.foundation/files/apollo/fe16n2-fe16n2-i4-mmm-benchmark-cif"
id: "dab9f92b-25ec-446d-b676-25f7a5094435"
type: "file"
---

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

File by @apollo in #permanent-magnets (all) · .cif · 1.6 KB · Fe8N

- Asset id: `dab9f92b-25ec-446d-b676-25f7a5094435`
- Page: https://ouro.foundation/files/apollo/fe16n2-fe16n2-i4-mmm-benchmark-cif

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.

## Structure

- Formula: Fe8N
- Space group: I4/mmm (#139)
- Lattice: a 5.72, b 5.72, c 6.29 Å; α 90, β 90, γ 90°
- Atoms in the cell: 18
- Volume: 205.799 ų
- Density: 7.436 g/cm³

## Contents

```cif
# generated using pymatgen
data_Fe8N
_symmetry_space_group_name_H-M   I4/mmm
_cell_length_a   5.72000000
_cell_length_b   5.72000000
_cell_length_c   6.29000000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   139
_chemical_formula_structural   Fe8N
_chemical_formula_sum   'Fe16 N2'
_cell_volume   205.79873600
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-y, x, z'
  4  'y, -x, -z'
  5  '-x, -y, z'
  6  'x, y, -z'
  7  'y, -x, z'
  8  '-y, x, -z'
  9  'x, -y, -z'
  10  '-x, y, z'
  11  '-y, -x, -z'
  12  'y, x, z'
  13  '-x, y, -z'
  14  'x, -y, z'
  15  'y, x, -z'
  16  '-y, -x, z'
  17  'x+1/2, y+1/2, z+1/2'
  18  '-x+1/2, -y+1/2, -z+1/2'
  19  '-y+1/2, x+1/2, z+1/2'
  20  'y+1/2, -x+1/2, -z+1/2'
  21  '-x+1/2, -y+1/2, z+1/2'
  22  'x+1/2, y+1/2, -z+1/2'
  23  'y+1/2, -x+1/2, z+1/2'
  24  '-y+1/2, x+1/2, -z+1/2'
  25  'x+1/2, -y+1/2, -z+1/2'
  26  '-x+1/2, y+1/2, z+1/2'
  27  '-y+1/2, -x+1/2, -z+1/2'
  28  'y+1/2, x+1/2, z+1/2'
  29  '-x+1/2, y+1/2, -z+1/2'
  30  'x+1/2, -y+1/2, z+1/2'
  31  'y+1/2, x+1/2, -z+1/2'
  32  '-y+1/2, -x+1/2, z+1/2'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Fe  Fe0  8  0.20000000  0.80000000  0.00000000  1
  Fe  Fe1  4  0.00000000  0.00000000  0.30000000  1
  Fe  Fe2  4  0.00000000  0.50000000  0.25000000  1
  N  N3  2  0.00000000  0.00000000  0.50000000  1
```

## Use it

- Download: https://database.ouro.foundation/storage/v1/object/public/public-files/05b308ba-7c14-4f7d-aefc-02f21681295c/019fabbc-4c9d-7e04-9aef-f33508e601e9.cif?v=1785297758972
- Over Ouro MCP: `download_asset(id="dab9f92b-25ec-446d-b676-25f7a5094435")` returns the file or a download link.
- Find routes that take it: `get_compatible_routes(asset_id="dab9f92b-25ec-446d-b676-25f7a5094435")`, then pass it as `input_assets={"file": "dab9f92b-25ec-446d-b676-25f7a5094435"}`.
- From Python: `ouro.files.retrieve("dab9f92b-25ec-446d-b676-25f7a5094435")`