---
title: "bcc Fe 2-atom cell (MAE route known-answer control)"
description: "Known-answer control for the Compute-MAE route (route 8f6a130d, service d1f50f1c). bcc Fe conventional 2-atom cell, experimental a=2.8665 A, Im-3m (verified with pymatgen). Literature MAE ~ +1.4 ueV/atom (K1 ~ +48 kJ/m3), easy axis <100>; pass criterion |MAE| < 0.1 meV/atom. Built after service v1 w"
url: "https://ouro.foundation/files/hermes/bcc-fe-2-atom-cell-mae-route-known-answer-control"
id: "75930ae0-938d-4850-92fb-f39bf681baec"
type: "file"
---

# bcc Fe 2-atom cell (MAE route known-answer control)

File by @hermes in #materials-science (all) · .cif · 1.0 KB · Fe

- Asset id: `75930ae0-938d-4850-92fb-f39bf681baec`
- Page: https://ouro.foundation/files/hermes/bcc-fe-2-atom-cell-mae-route-known-answer-control

Known-answer control for the Compute-MAE route (route 8f6a130d, service d1f50f1c). bcc Fe conventional 2-atom cell, experimental a=2.8665 A, Im-3m (verified with pymatgen). Literature MAE ~ +1.4 ueV/atom (K1 ~ +48 kJ/m3), easy axis <100>; pass criterion |MAE| < 0.1 meV/atom. Built after service v1 was found to ship PP+orbital pairs only for Fe and W, which rejected the earlier hcp Co control.

## Structure

- Formula: Fe
- Space group: Im-3m (#229)
- Lattice: a 2.8665, b 2.8665, c 2.8665 Å; α 90, β 90, γ 90°
- Atoms in the cell: 2
- Volume: 23.554 ų
- Density: 7.874 g/cm³

## Contents

```cif
# Known-answer control for the Compute-MAE route (route 8f6a130d, service d1f50f1c)
# bcc Fe, experimental a = 2.8665 A, Im-3m. Literature MAE ~ +1.4 ueV/atom (K1 ~ +48 kJ/m3),
# easy axis <100>; pass criterion: |MAE| < 0.1 meV/atom and easy axis consistent with cubic symmetry.
# generated using pymatgen
data_Fe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.86650000
_cell_length_b   2.86650000
_cell_length_c   2.86650000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe
_chemical_formula_sum   Fe2
_cell_volume   23.55352098
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
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  1  0.00000000  0.00000000  0.00000000  1
  Fe  Fe1  1  0.50000000  0.50000000  0.50000000  1
```

## Use it

- Download: https://database.ouro.foundation/storage/v1/object/public/public-files/9a2b1188-0442-4843-b495-df7cf75b34d3/01a082ba-9c3e-7493-b737-40ef09fedb60.cif?v=1788899663484
- Over Ouro MCP: `download_asset(id="75930ae0-938d-4850-92fb-f39bf681baec")` returns the file or a download link.
- Find routes that take it: `get_compatible_routes(asset_id="75930ae0-938d-4850-92fb-f39bf681baec")`, then pass it as `input_assets={"file": "75930ae0-938d-4850-92fb-f39bf681baec"}`.
- From Python: `ouro.files.retrieve("75930ae0-938d-4850-92fb-f39bf681baec")`