NaHSeO4 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form NaO6 octahedra that share corners with three equivalent Se(1)O4 tetrahedra, corners with three equivalent Se(2)O4 tetrahedra, and edges with two equivalent Na(2)O6 octahedra. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form NaO6 octahedra that share corners with three equivalent Se(1)O4 tetrahedra, corners with three equivalent Se(2)O4 tetrahedra, and edges with two equivalent Na(1)O6 octahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(7) and one O(8) atom. In the second H site, H(2) is bonded in a linear geometry to one O(5) and one O(6) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form SeO4 tetrahedra that share corners with three equivalent Na(1)O6 octahedra and corners with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Se site, Se(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form SeO4 tetrahedra that share corners with three equivalent Na(1)O6 octahedra and corners with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(2), one H(2), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one H(2), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Na(1), one H(1), and one Se(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Na(2), one H(1), and one Se(2) atom.
NaHSeO4 crystallizes in the triclinic P1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form NaO6 octahedra that share corners with three equivalent Se(1)O4 tetrahedra, corners with three equivalent Se(2)O4 tetrahedra, and edges with two equivalent Na(2)O6 octahedra. The Na(1)-O(1) bond length is 2.43 Å. The Na(1)-O(2) bond length is 2.44 Å. The Na(1)-O(3) bond length is 2.46 Å. The Na(1)-O(4) bond length is 2.35 Å. The Na(1)-O(6) bond length is 2.44 Å. The Na(1)-O(7) bond length is 2.51 Å. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form NaO6 octahedra that share corners with three equivalent Se(1)O4 tetrahedra, corners with three equivalent Se(2)O4 tetrahedra, and edges with two equivalent Na(1)O6 octahedra. The Na(2)-O(1) bond length is 2.45 Å. The Na(2)-O(2) bond length is 2.55 Å. The Na(2)-O(3) bond length is 2.37 Å. The Na(2)-O(4) bond length is 2.41 Å. The Na(2)-O(5) bond length is 2.46 Å. The Na(2)-O(8) bond length is 2.53 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(7) and one O(8) atom. The H(1)-O(7) bond length is 1.03 Å. The H(1)-O(8) bond length is 1.57 Å. In the second H site, H(2) is bonded in a linear geometry to one O(5) and one O(6) atom. The H(2)-O(5) bond length is 1.52 Å. The H(2)-O(6) bond length is 1.04 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form SeO4 tetrahedra that share corners with three equivalent Na(1)O6 octahedra and corners with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. The Se(1)-O(1) bond length is 1.64 Å. The Se(1)-O(3) bond length is 1.65 Å. The Se(1)-O(5) bond length is 1.67 Å. The Se(1)-O(7) bond length is 1.77 Å. In the second Se site, Se(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form SeO4 tetrahedra that share corners with three equivalent Na(1)O6 octahedra and corners with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. The Se(2)-O(2) bond length is 1.64 Å. The Se(2)-O(4) bond length is 1.65 Å. The Se(2)-O(6) bond length is 1.76 Å. The Se(2)-O(8) bond length is 1.67 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Na(2), one H(2), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one H(2), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Na(1), one H(1), and one Se(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Na(2), one H(1), and one Se(2) atom.