Hf4GeSb7 crystallizes in the monoclinic Pm space group. There are four inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 9-coordinate geometry to one Ge(1), one Sb(2), one Sb(5), two equivalent Sb(3), two equivalent Sb(4), and two equivalent Sb(6) atoms. In the second Hf site, Hf(2) is bonded in a 9-coordinate geometry to one Ge(1), one Sb(1), one Sb(5), two equivalent Sb(3), two equivalent Sb(4), and two equivalent Sb(7) atoms. In the third Hf site, Hf(3) is bonded in a 9-coordinate geometry to two equivalent Ge(1), one Sb(4), one Sb(6), one Sb(7), two equivalent Sb(1), and two equivalent Sb(2) atoms. In the fourth Hf site, Hf(4) is bonded in a 9-coordinate geometry to one Sb(3), one Sb(6), one Sb(7), two equivalent Sb(1), two equivalent Sb(2), and two equivalent Sb(5) atoms. Ge(1) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(3), two equivalent Sb(4), and two equivalent Sb(6) atoms. There are seven inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 7-coordinate geometry to one Hf(2), two equivalent Hf(3), two equivalent Hf(4), and two equivalent Sb(7) atoms. In the second Sb site, Sb(2) is bonded in a 5-coordinate geometry to one Hf(1), two equivalent Hf(3), and two equivalent Hf(4) atoms. In the third Sb site, Sb(3) is bonded in a 7-coordinate geometry to one Hf(4), two equivalent Hf(1), two equivalent Hf(2), and two equivalent Sb(5) atoms. In the fourth Sb site, Sb(4) is bonded in a 7-coordinate geometry to one Hf(3), two equivalent Hf(1), two equivalent Hf(2), and two equivalent Ge(1) atoms. In the fifth Sb site, Sb(5) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(4), two equivalent Sb(3), and two equivalent Sb(7) atoms. In the sixth Sb site, Sb(6) is bonded in a 6-coordinate geometry to one Hf(3), one Hf(4), two equivalent Hf(1), and two equivalent Ge(1) atoms. In the seventh Sb site, Sb(7) is bonded in a 8-coordinate geometry to one Hf(3), one Hf(4), two equivalent Hf(2), two equivalent Sb(1), and two equivalent Sb(5) atoms.
Hf4GeSb7 crystallizes in the monoclinic Pm space group. There are four inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 9-coordinate geometry to one Ge(1), one Sb(2), one Sb(5), two equivalent Sb(3), two equivalent Sb(4), and two equivalent Sb(6) atoms. The Hf(1)-Ge(1) bond length is 3.05 Å. The Hf(1)-Sb(2) bond length is 3.15 Å. The Hf(1)-Sb(5) bond length is 2.93 Å. Both Hf(1)-Sb(3) bond lengths are 3.01 Å. Both Hf(1)-Sb(4) bond lengths are 3.08 Å. Both Hf(1)-Sb(6) bond lengths are 2.94 Å. In the second Hf site, Hf(2) is bonded in a 9-coordinate geometry to one Ge(1), one Sb(1), one Sb(5), two equivalent Sb(3), two equivalent Sb(4), and two equivalent Sb(7) atoms. The Hf(2)-Ge(1) bond length is 2.82 Å. The Hf(2)-Sb(1) bond length is 3.31 Å. The Hf(2)-Sb(5) bond length is 3.10 Å. Both Hf(2)-Sb(3) bond lengths are 2.99 Å. Both Hf(2)-Sb(4) bond lengths are 3.01 Å. Both Hf(2)-Sb(7) bond lengths are 3.00 Å. In the third Hf site, Hf(3) is bonded in a 9-coordinate geometry to two equivalent Ge(1), one Sb(4), one Sb(6), one Sb(7), two equivalent Sb(1), and two equivalent Sb(2) atoms. Both Hf(3)-Ge(1) bond lengths are 2.92 Å. The Hf(3)-Sb(4) bond length is 3.08 Å. The Hf(3)-Sb(6) bond length is 2.94 Å. The Hf(3)-Sb(7) bond length is 2.95 Å. Both Hf(3)-Sb(1) bond lengths are 3.04 Å. Both Hf(3)-Sb(2) bond lengths are 3.02 Å. In the fourth Hf site, Hf(4) is bonded in a 9-coordinate geometry to one Sb(3), one Sb(6), one Sb(7), two equivalent Sb(1), two equivalent Sb(2), and two equivalent Sb(5) atoms. The Hf(4)-Sb(3) bond length is 3.28 Å. The Hf(4)-Sb(6) bond length is 2.97 Å. The Hf(4)-Sb(7) bond length is 3.09 Å. Both Hf(4)-Sb(1) bond lengths are 3.00 Å. Both Hf(4)-Sb(2) bond lengths are 3.02 Å. Both Hf(4)-Sb(5) bond lengths are 2.98 Å. Ge(1) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(3), two equivalent Sb(4), and two equivalent Sb(6) atoms. Both Ge(1)-Sb(4) bond lengths are 3.03 Å. Both Ge(1)-Sb(6) bond lengths are 2.78 Å. There are seven inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 7-coordinate geometry to one Hf(2), two equivalent Hf(3), two equivalent Hf(4), and two equivalent Sb(7) atoms. Both Sb(1)-Sb(7) bond lengths are 3.12 Å. In the second Sb site, Sb(2) is bonded in a 5-coordinate geometry to one Hf(1), two equivalent Hf(3), and two equivalent Hf(4) atoms. In the third Sb site, Sb(3) is bonded in a 7-coordinate geometry to one Hf(4), two equivalent Hf(1), two equivalent Hf(2), and two equivalent Sb(5) atoms. Both Sb(3)-Sb(5) bond lengths are 3.13 Å. In the fourth Sb site, Sb(4) is bonded in a 7-coordinate geometry to one Hf(3), two equivalent Hf(1), two equivalent Hf(2), and two equivalent Ge(1) atoms. In the fifth Sb site, Sb(5) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(4), two equivalent Sb(3), and two equivalent Sb(7) atoms. Both Sb(5)-Sb(7) bond lengths are 2.92 Å. In the sixth Sb site, Sb(6) is bonded in a 6-coordinate geometry to one Hf(3), one Hf(4), two equivalent Hf(1), and two equivalent Ge(1) atoms. In the seventh Sb site, Sb(7) is bonded in a 8-coordinate geometry to one Hf(3), one Hf(4), two equivalent Hf(2), two equivalent Sb(1), and two equivalent Sb(5) atoms.