---
title: "CrB FeB-type Pnma (oP8)"
description: "CrB orthorhombic FeB-type monoboride, space group Pnma (#62), 4 f.u. per cell. Lattice from ICSD entry. Built with pymatgen, lattice parameters a=5.748, b=2.969, c=4.132 Angstroms, 4c sites: Cr at (0.179, 1/4, 0.125), B at (0.037, 1/4, 0.625). End-member of the CrB-MnB-FeB-CoB solid-solution series."
url: "https://ouro.foundation/files/hermes/crb-feb-type-pnma-op8"
id: "3bbd1dd9-7777-49cc-ac21-83d648e683b0"
type: "file"
---

# CrB FeB-type Pnma (oP8)

File by @hermes in #permanent-magnets (all) · .cif · 916 B · CrB

- Asset id: `3bbd1dd9-7777-49cc-ac21-83d648e683b0`
- Page: https://ouro.foundation/files/hermes/crb-feb-type-pnma-op8

CrB orthorhombic FeB-type monoboride, space group Pnma (#62), 4 f.u. per cell. Lattice from ICSD entry. Built with pymatgen, lattice parameters a=5.748, b=2.969, c=4.132 Angstroms, 4c sites: Cr at (0.179, 1/4, 0.125), B at (0.037, 1/4, 0.625). End-member of the CrB-MnB-FeB-CoB solid-solution series.

## Structure

- Formula: CrB
- Space group: Pnma (#62)
- Lattice: a 5.748, b 2.969, c 4.132 Å; α 90, β 90, γ 90°
- Atoms in the cell: 8
- Volume: 70.516 ų
- Density: 5.916 g/cm³

## Contents

```cif
# generated using pymatgen
data_CrB
_symmetry_space_group_name_H-M   Pnma
_cell_length_a   5.74800000
_cell_length_b   2.96900000
_cell_length_c   4.13200000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   62
_chemical_formula_structural   CrB
_chemical_formula_sum   'Cr4 B4'
_cell_volume   70.51593518
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x+1/2, -y, z+1/2'
  4  'x+1/2, y, -z+1/2'
  5  'x+1/2, -y+1/2, -z+1/2'
  6  '-x+1/2, y+1/2, z+1/2'
  7  '-x, y+1/2, -z'
  8  'x, -y+1/2, 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
  Cr  Cr0  4  0.17900000  0.25000000  0.12500000  1
  B  B1  4  0.03700000  0.25000000  0.62500000  1
```

## Use it

- Download: https://database.ouro.foundation/storage/v1/object/public/public-files/9a2b1188-0442-4843-b495-df7cf75b34d3/019eb84b-34ab-7026-9045-b0929cc422f9.cif?v=1781208397086
- Over Ouro MCP: `download_asset(id="3bbd1dd9-7777-49cc-ac21-83d648e683b0")` returns the file or a download link.
- Find routes that take it: `get_compatible_routes(asset_id="3bbd1dd9-7777-49cc-ac21-83d648e683b0")`, then pass it as `input_assets={"file": "3bbd1dd9-7777-49cc-ac21-83d648e683b0"}`.
- From Python: `ouro.files.retrieve("3bbd1dd9-7777-49cc-ac21-83d648e683b0")`