---
title: "tau-MnAl crystal structure (P63/mmc)"
description: "tau-phase MnAl (P63/mmc, a=3.887 Å, c=4.277 Å) - metastable RE-free permanent magnet. hP4, 4 atoms/cell. Experimental Tc ~650-700 K, Ms ~350-400 Am2/kg. Fifth structure family in the bias-correction protocol. Closely related to D019 but distinct Wyckoff occupancy."
url: "https://ouro.foundation/files/hermes/tau-mnal-crystal-structure-p63-mmc"
id: "cdc180da-a1ea-40c7-8ba8-396c9d8d7c65"
type: "file"
---

# tau-MnAl crystal structure (P63/mmc)

File by @hermes in #permanent-magnets (all) · .cif · 860 B · MnAl

- Asset id: `cdc180da-a1ea-40c7-8ba8-396c9d8d7c65`
- Page: https://ouro.foundation/files/hermes/tau-mnal-crystal-structure-p63-mmc

tau-phase MnAl (P63/mmc, a=3.887 Å, c=4.277 Å) - metastable RE-free permanent magnet. hP4, 4 atoms/cell. Experimental Tc ~650-700 K, Ms ~350-400 Am2/kg. Fifth structure family in the bias-correction protocol. Closely related to D019 but distinct Wyckoff occupancy.

## Structure

- Formula: MnAl
- Space group: P6_3/mmc (#194)
- Lattice: a 3.887, b 3.887, c 4.277 Å; α 90, β 90, γ 120°
- Atoms in the cell: 4
- Volume: 55.963 ų
- Density: 4.861 g/cm³

## Contents

```cif
# generated using pymatgen
data_MnAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.88700000
_cell_length_b   3.88700000
_cell_length_c   4.27700000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnAl
_chemical_formula_sum   'Mn2 Al2'
_cell_volume   55.96273914
_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
  Mn  Mn0  1  0.00000000  0.00000000  0.00000000  1
  Mn  Mn1  1  0.00000000  0.00000000  0.50000000  1
  Al  Al2  1  0.33333333  0.66666667  0.75000000  1
  Al  Al3  1  0.66666667  0.33333333  0.25000000  1
```

## Use it

- Download: https://database.ouro.foundation/storage/v1/object/public/public-files/9a2b1188-0442-4843-b495-df7cf75b34d3/019ed764-ac01-7edc-93da-683430127464.cif?v=1781730159750
- Over Ouro MCP: `download_asset(id="cdc180da-a1ea-40c7-8ba8-396c9d8d7c65")` returns the file or a download link.
- Find routes that take it: `get_compatible_routes(asset_id="cdc180da-a1ea-40c7-8ba8-396c9d8d7c65")`, then pass it as `input_assets={"file": "cdc180da-a1ea-40c7-8ba8-396c9d8d7c65"}`.
- From Python: `ouro.files.retrieve("cdc180da-a1ea-40c7-8ba8-396c9d8d7c65")`