Fe3B is Cementite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to three equivalent B(1) atoms. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to three equivalent B(1) atoms. B(1) is bonded in a 9-coordinate geometry to three equivalent Fe(1) and six equivalent Fe(2) atoms.
Fe3B is Cementite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to three equivalent B(1) atoms. There are two shorter (2.13 Å) and one longer (2.49 Å) Fe(1)-B(1) bond length. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to three equivalent B(1) atoms. There are a spread of Fe(2)-B(1) bond distances ranging from 2.07-2.28 Å. B(1) is bonded in a 9-coordinate geometry to three equivalent Fe(1) and six equivalent Fe(2) atoms.