Er4Ir7Ge6 crystallizes in the cubic Im-3m space group. Er(1) is bonded to six equivalent Ir(1) and six equivalent Ge(1) atoms to form ErGe6Ir6 cuboctahedra that share corners with twelve equivalent Er(1)Ge6Ir6 cuboctahedra, faces with six equivalent Er(1)Ge6Ir6 cuboctahedra, and faces with two equivalent Ir(2)Ge6 octahedra. There are two inequivalent Ir sites. In the first Ir site, Ir(2) is bonded to six equivalent Ge(1) atoms to form IrGe6 octahedra that share faces with eight equivalent Er(1)Ge6Ir6 cuboctahedra. In the second Ir site, Ir(1) is bonded in a 8-coordinate geometry to four equivalent Er(1) and four equivalent Ge(1) atoms. Ge(1) is bonded in a 9-coordinate geometry to four equivalent Er(1), one Ir(2), and four equivalent Ir(1) atoms.
Er4Ir7Ge6 crystallizes in the cubic Im-3m space group. Er(1) is bonded to six equivalent Ir(1) and six equivalent Ge(1) atoms to form ErGe6Ir6 cuboctahedra that share corners with twelve equivalent Er(1)Ge6Ir6 cuboctahedra, faces with six equivalent Er(1)Ge6Ir6 cuboctahedra, and faces with two equivalent Ir(2)Ge6 octahedra. All Er(1)-Ir(1) bond lengths are 2.94 Å. All Er(1)-Ge(1) bond lengths are 2.99 Å. There are two inequivalent Ir sites. In the first Ir site, Ir(2) is bonded to six equivalent Ge(1) atoms to form IrGe6 octahedra that share faces with eight equivalent Er(1)Ge6Ir6 cuboctahedra. All Ir(2)-Ge(1) bond lengths are 2.64 Å. In the second Ir site, Ir(1) is bonded in a 8-coordinate geometry to four equivalent Er(1) and four equivalent Ge(1) atoms. All Ir(1)-Ge(1) bond lengths are 2.57 Å. Ge(1) is bonded in a 9-coordinate geometry to four equivalent Er(1), one Ir(2), and four equivalent Ir(1) atoms.