Fe3Ni crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to two equivalent Fe(2), four equivalent Fe(1), and two equivalent Ni(1) atoms. In the second Fe site, Fe(2) is bonded in a distorted body-centered cubic geometry to four equivalent Fe(1) and four equivalent Fe(2) atoms. Ni(1) is bonded in a 8-coordinate geometry to four equivalent Fe(1) and four equivalent Ni(1) atoms.
Fe3Ni crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to two equivalent Fe(2), four equivalent Fe(1), and two equivalent Ni(1) atoms. Both Fe(1)-Fe(2) bond lengths are 2.47 Å. All Fe(1)-Fe(1) bond lengths are 2.46 Å. Both Fe(1)-Ni(1) bond lengths are 2.46 Å. In the second Fe site, Fe(2) is bonded in a distorted body-centered cubic geometry to four equivalent Fe(1) and four equivalent Fe(2) atoms. All Fe(2)-Fe(2) bond lengths are 2.46 Å. Ni(1) is bonded in a 8-coordinate geometry to four equivalent Fe(1) and four equivalent Ni(1) atoms. All Ni(1)-Ni(1) bond lengths are 2.46 Å.