Fe3(Ni10B3)2 crystallizes in the cubic Fm-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a cuboctahedral geometry to twelve equivalent Ni(1) atoms. In the second Fe site, Fe(2) is bonded in a distorted tetrahedral geometry to four equivalent Ni(2) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and two equivalent B(1) atoms. In the second Ni site, Ni(2) is bonded to one Fe(2) and three equivalent B(1) atoms to form a mixture of distorted edge and corner-sharing NiFeB3 tetrahedra. B(1) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Ni(2) atoms.
Fe3(Ni10B3)2 crystallizes in the cubic Fm-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a cuboctahedral geometry to twelve equivalent Ni(1) atoms. All Fe(1)-Ni(1) bond lengths are 2.50 Å. In the second Fe site, Fe(2) is bonded in a distorted tetrahedral geometry to four equivalent Ni(2) atoms. All Fe(2)-Ni(2) bond lengths are 2.41 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and two equivalent B(1) atoms. Both Ni(1)-B(1) bond lengths are 2.07 Å. In the second Ni site, Ni(2) is bonded to one Fe(2) and three equivalent B(1) atoms to form a mixture of distorted edge and corner-sharing NiFeB3 tetrahedra. All Ni(2)-B(1) bond lengths are 2.09 Å. B(1) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Ni(2) atoms.