AlH5(SeO4)2 crystallizes in the monoclinic P2_1/c space group. Al(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a linear geometry to two equivalent O(3) atoms. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one H(1), and one H(3) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Al(1) and one Se(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one H(2) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Al(1) and one Se(1) atom.
AlH5(SeO4)2 crystallizes in the monoclinic P2_1/c space group. Al(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Both Al(1)-O(1) bond lengths are 1.97 Å. Both Al(1)-O(2) bond lengths are 1.90 Å. Both Al(1)-O(4) bond lengths are 1.88 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 1.00 Å. In the second H site, H(2) is bonded in a linear geometry to two equivalent O(3) atoms. Both H(2)-O(3) bond lengths are 1.23 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. The H(3)-O(1) bond length is 0.99 Å. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(4) atom. The Se(1)-O(2) bond length is 1.71 Å. The Se(1)-O(3) bond length is 1.78 Å. The Se(1)-O(4) bond length is 1.72 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one H(1), and one H(3) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Al(1) and one Se(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one H(2) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Al(1) and one Se(1) atom.