BeH2SeO4 crystallizes in the orthorhombic P2_12_12_1 space group. Be(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) and one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) atom. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Be(1), one H(1), and one Se(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Be(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Be(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Be(1), one H(1), and one H(2) atom.
BeH2SeO4 crystallizes in the orthorhombic P2_12_12_1 space group. Be(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Be(1)-O(1) bond length is 1.64 Å. The Be(1)-O(2) bond length is 1.63 Å. The Be(1)-O(3) bond length is 1.63 Å. The Be(1)-O(4) bond length is 1.67 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) and one O(4) atom. The H(1)-O(1) bond length is 1.74 Å. The H(1)-O(4) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) atom. The H(2)-O(4) bond length is 0.99 Å. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The Se(1)-O(1) bond length is 1.74 Å. The Se(1)-O(2) bond length is 1.73 Å. The Se(1)-O(3) bond length is 1.73 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Be(1), one H(1), and one Se(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Be(1) and one Se(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Be(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Be(1), one H(1), and one H(2) atom.