Hf(CoGe)6 crystallizes in the hexagonal P6/mmm space group. Hf(1) is bonded to twelve equivalent Co(1), two equivalent Ge(3), and six equivalent Ge(1) atoms to form distorted face-sharing HfCo12Ge8 hexagonal bipyramids. Co(1) is bonded in a 12-coordinate geometry to two equivalent Hf(1), four equivalent Co(1), two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1) and six equivalent Co(1) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to one Hf(1), six equivalent Co(1), and one Ge(3) atom.
Hf(CoGe)6 crystallizes in the hexagonal P6/mmm space group. Hf(1) is bonded to twelve equivalent Co(1), two equivalent Ge(3), and six equivalent Ge(1) atoms to form distorted face-sharing HfCo12Ge8 hexagonal bipyramids. All Hf(1)-Co(1) bond lengths are 3.18 Å. Both Hf(1)-Ge(3) bond lengths are 2.65 Å. All Hf(1)-Ge(1) bond lengths are 2.91 Å. Co(1) is bonded in a 12-coordinate geometry to two equivalent Hf(1), four equivalent Co(1), two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. All Co(1)-Co(1) bond lengths are 2.52 Å. Both Co(1)-Ge(1) bond lengths are 2.43 Å. Both Co(1)-Ge(2) bond lengths are 2.44 Å. Both Co(1)-Ge(3) bond lengths are 2.62 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1) and six equivalent Co(1) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to one Hf(1), six equivalent Co(1), and one Ge(3) atom. The Ge(3)-Ge(3) bond length is 2.50 Å.