Hf(SeCl6)2 crystallizes in the orthorhombic Fdd2 space group. Hf(1) is bonded in an octahedral geometry to two equivalent Cl(2), two equivalent Cl(4), and two equivalent Cl(5) atoms. Se(1) is bonded in a 6-coordinate geometry to one Cl(1), one Cl(2), one Cl(3), one Cl(4), one Cl(5), and one Cl(6) atom. There are six inequivalent Cl sites. In the first Cl site, Cl(6) is bonded in a single-bond geometry to one Se(1) atom. In the second Cl site, Cl(1) is bonded in a single-bond geometry to one Se(1) atom. In the third Cl site, Cl(2) is bonded in a distorted water-like geometry to one Hf(1) and one Se(1) atom. In the fourth Cl site, Cl(3) is bonded in a single-bond geometry to one Se(1) atom. In the fifth Cl site, Cl(4) is bonded in a distorted single-bond geometry to one Hf(1) and one Se(1) atom. In the sixth Cl site, Cl(5) is bonded in a distorted water-like geometry to one Hf(1) and one Se(1) atom.
Hf(SeCl6)2 crystallizes in the orthorhombic Fdd2 space group. Hf(1) is bonded in an octahedral geometry to two equivalent Cl(2), two equivalent Cl(4), and two equivalent Cl(5) atoms. Both Hf(1)-Cl(2) bond lengths are 2.45 Å. Both Hf(1)-Cl(4) bond lengths are 2.44 Å. Both Hf(1)-Cl(5) bond lengths are 2.47 Å. Se(1) is bonded in a 6-coordinate geometry to one Cl(1), one Cl(2), one Cl(3), one Cl(4), one Cl(5), and one Cl(6) atom. The Se(1)-Cl(1) bond length is 2.17 Å. The Se(1)-Cl(2) bond length is 2.80 Å. The Se(1)-Cl(3) bond length is 2.18 Å. The Se(1)-Cl(4) bond length is 2.89 Å. The Se(1)-Cl(5) bond length is 2.83 Å. The Se(1)-Cl(6) bond length is 2.18 Å. There are six inequivalent Cl sites. In the first Cl site, Cl(6) is bonded in a single-bond geometry to one Se(1) atom. In the second Cl site, Cl(1) is bonded in a single-bond geometry to one Se(1) atom. In the third Cl site, Cl(2) is bonded in a distorted water-like geometry to one Hf(1) and one Se(1) atom. In the fourth Cl site, Cl(3) is bonded in a single-bond geometry to one Se(1) atom. In the fifth Cl site, Cl(4) is bonded in a distorted single-bond geometry to one Hf(1) and one Se(1) atom. In the sixth Cl site, Cl(5) is bonded in a distorted water-like geometry to one Hf(1) and one Se(1) atom.