Er(Co2Ge)2 crystallizes in the tetragonal P4_2/mnm space group. Er(1) is bonded to six equivalent Ge(1) atoms to form a mixture of distorted corner and edge-sharing ErGe6 octahedra. The corner-sharing octahedral tilt angles are 39°. Co(1) is bonded in a 3-coordinate geometry to three equivalent Ge(1) atoms. Ge(1) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent Co(1) atoms.
Er(Co2Ge)2 crystallizes in the tetragonal P4_2/mnm space group. Er(1) is bonded to six equivalent Ge(1) atoms to form a mixture of distorted corner and edge-sharing ErGe6 octahedra. The corner-sharing octahedral tilt angles are 39°. There are two shorter (2.84 Å) and four longer (2.92 Å) Er(1)-Ge(1) bond lengths. Co(1) is bonded in a 3-coordinate geometry to three equivalent Ge(1) atoms. All Co(1)-Ge(1) bond lengths are 2.39 Å. Ge(1) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent Co(1) atoms.