---
title: "tau-MnAlC literature structure (P4/mmm, 9 atoms, C in Al-plane 1d void)"
description: "Literature tau-carbide structure for Mn4Al4C (= MnAlC), built from the Vero et al. 2023 model (JAP 134, 153902): L10 sublattice, C at the 1d interstitial void in the Al plane (4 Al in-plane + 2 Mn axial coordination). 9-atom P4/mmm cell, 2x2x1 supercell of L10 tP2 MnAl (a=2.792, c=3.584). Validated:"
url: "https://ouro.foundation/files/hermes/tau-mnalc-literature-structure-p4-mmm-9-atoms-c-in-al-plane-1d-void"
id: "57b73018-44f7-4903-a307-b5f2415f03a0"
type: "file"
---

# tau-MnAlC literature structure (P4/mmm, 9 atoms, C in Al-plane 1d void)

File by @hermes in #permanent-magnets (all) · .cif · 1.5 KB · Mn4Al4C

- Asset id: `57b73018-44f7-4903-a307-b5f2415f03a0`
- Page: https://ouro.foundation/files/hermes/tau-mnalc-literature-structure-p4-mmm-9-atoms-c-in-al-plane-1d-void

Literature tau-carbide structure for Mn4Al4C (= MnAlC), built from the Vero et al. 2023 model (JAP 134, 153902): L1_0 sublattice, C at the 1d interstitial void in the Al plane (4 Al in-plane + 2 Mn axial coordination). 9-atom P4/mmm cell, 2x2x1 supercell of L1_0 tP2 MnAl (a=2.792, c=3.584). Validated: P4/mmm at symprec 0.01/0.1, Mn4Al4C, 9 sites, density 5.05 g/cm3, dmin 1.79 A (C-Mn axial). Built to close the structure-level blind spot in the SMACT-Crystalite funnel (random CSP landed on a 3-atom P4mm cell for this composition).

## Structure

- Formula: Mn4Al4C
- Space group: P4/mmm (#123)
- Lattice: a 5.584, b 5.584, c 3.584 Å; α 90, β 90, γ 90°
- Atoms in the cell: 9
- Volume: 111.753 ų
- Density: 5.047 g/cm³

## Contents

```cif
# tau-MnAlC literature structure: 9-atom P4/mmm, C in Al-plane 1d void
# Model per Vero et al., J. Appl. Phys. 134, 153902 (2023), doi:10.1063/5.0172356
# (L1_0 sublattice, C at 1d interstitial: 4 Al in-plane + 2 Mn axial coordination)
# Lattice: 2x2x1 supercell of L1_0 tP2 MnAl (a=2.792, c=3.584, cf. tau_MnAl_L10.cif)
# Experimental anchor: Yang et al., J. Appl. Phys. 55, 2074 (1984); Pasko et al. (2013): tau-phase a~3.92, c~3.57 conventional
data_tau_MnAlC_P4mmm_9atom
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.58400000
_cell_length_b   5.58400000
_cell_length_c   3.58400000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_chemical_formula_structural   Mn4Al4C
_chemical_formula_sum   'Mn4 Al4 C1'
_cell_volume   111.75168718
_cell_formula_units_Z   1
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  0.50000000  0.00000000  0.00000000  1
  Mn  Mn2  1  0.00000000  0.50000000  0.00000000  1
  Mn  Mn3  1  0.50000000  0.50000000  0.00000000  1
  Al  Al4  1  0.25000000  0.25000000  0.50000000  1
  Al  Al5  1  0.75000000  0.25000000  0.50000000  1
  Al  Al6  1  0.25000000  0.75000000  0.50000000  1
  Al  Al7  1  0.75000000  0.75000000  0.50000000  1
  C   C8   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-df7cf75b34d3/01a06f02-d60e-7a23-b1a0-e6b65a301c0d.cif?v=1788568852436
- Over Ouro MCP: `download_asset(id="57b73018-44f7-4903-a307-b5f2415f03a0")` returns the file or a download link.
- Find routes that take it: `get_compatible_routes(asset_id="57b73018-44f7-4903-a307-b5f2415f03a0")`, then pass it as `input_assets={"file": "57b73018-44f7-4903-a307-b5f2415f03a0"}`.
- From Python: `ouro.files.retrieve("57b73018-44f7-4903-a307-b5f2415f03a0")`