Na3H5(SeO4)4 crystallizes in the triclinic P1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(12), one O(16), one O(2), and one O(9) atom to form NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Se(1)O4 tetrahedra,  a cornercorner with one Se(4)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra, and edges with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles are 74°. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(11), one O(12), one O(15), and one O(2) atom to form NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Se(2)O4 tetrahedra,  a cornercorner with one Se(3)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(4)O4 tetrahedra, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. In the third Na site, Na(3) is bonded to one O(15), one O(16), one O(3), one O(4), one O(7), and one O(8) atom to form NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Se(3)O4 tetrahedra,  a cornercorner with one Se(4)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, and corners with two equivalent Se(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 70-74°. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(10) and one O(5) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) and one O(9) atom. In the third H site, H(3) is bonded in a linear geometry to one O(13) and one O(4) atom. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(14) and one O(3) atom. In the fifth H site, H(5) is bonded in a linear geometry to one O(7) and one O(8) atom. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(11), one O(13), one O(15), and one O(7) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, and corners with two equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-56°. In the second Se site, Se(2) is bonded to one O(12), one O(14), one O(16), and one O(8) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, and corners with two equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. In the third Se site, Se(3) is bonded to one O(1), one O(3), one O(5), and one O(9) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra, and corners with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-54°. In the fourth Se site, Se(4) is bonded to one O(10), one O(2), one O(4), and one O(6) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra, and corners with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-54°. There are sixteen 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(3) 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(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(3), one H(4), and one Se(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(3), one H(3), and one Se(4) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one H(1) and one Se(3) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one H(2) and one Se(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(3), one H(5), and one Se(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(3), one H(5), and one Se(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(1), one H(2), and one Se(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Na(2), one H(1), and one Se(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(2) atom. In the thirteenth O site, O(13) is bonded in a water-like geometry to one H(3) and one Se(1) atom. In the fourteenth O site, O(14) is bonded in a water-like geometry to one H(4) and one Se(2) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Na(2), one Na(3), and one Se(1) atom. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Na(1), one Na(3), and one Se(2) atom.
Na3H5(SeO4)4 crystallizes in the triclinic P1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(12), one O(16), one O(2), and one O(9) atom to form NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Se(1)O4 tetrahedra,  a cornercorner with one Se(4)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra, and edges with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles are 74°. The Na(1)-O(1) bond length is 2.43 Å. The Na(1)-O(11) bond length is 2.46 Å. The Na(1)-O(12) bond length is 2.41 Å. The Na(1)-O(16) bond length is 2.40 Å. The Na(1)-O(2) bond length is 2.46 Å. The Na(1)-O(9) bond length is 2.47 Å. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(11), one O(12), one O(15), and one O(2) atom to form NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Se(2)O4 tetrahedra,  a cornercorner with one Se(3)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(4)O4 tetrahedra, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. The Na(2)-O(1) bond length is 2.40 Å. The Na(2)-O(10) bond length is 2.45 Å. The Na(2)-O(11) bond length is 2.44 Å. The Na(2)-O(12) bond length is 2.44 Å. The Na(2)-O(15) bond length is 2.51 Å. The Na(2)-O(2) bond length is 2.43 Å. In the third Na site, Na(3) is bonded to one O(15), one O(16), one O(3), one O(4), one O(7), and one O(8) atom to form NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Se(3)O4 tetrahedra,  a cornercorner with one Se(4)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, and corners with two equivalent Se(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 70-74°. The Na(3)-O(15) bond length is 2.47 Å. The Na(3)-O(16) bond length is 2.42 Å. The Na(3)-O(3) bond length is 2.39 Å. The Na(3)-O(4) bond length is 2.40 Å. The Na(3)-O(7) bond length is 2.61 Å. The Na(3)-O(8) bond length is 2.44 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(10) and one O(5) atom. The H(1)-O(10) bond length is 1.75 Å. The H(1)-O(5) bond length is 1.01 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) and one O(9) atom. The H(2)-O(6) bond length is 1.01 Å. The H(2)-O(9) bond length is 1.71 Å. In the third H site, H(3) is bonded in a linear geometry to one O(13) and one O(4) atom. The H(3)-O(13) bond length is 1.04 Å. The H(3)-O(4) bond length is 1.55 Å. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(14) and one O(3) atom. The H(4)-O(14) bond length is 1.02 Å. The H(4)-O(3) bond length is 1.63 Å. In the fifth H site, H(5) is bonded in a linear geometry to one O(7) and one O(8) atom. The H(5)-O(7) bond length is 1.08 Å. The H(5)-O(8) bond length is 1.42 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(11), one O(13), one O(15), and one O(7) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, and corners with two equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-56°. The Se(1)-O(11) bond length is 1.64 Å. The Se(1)-O(13) bond length is 1.73 Å. The Se(1)-O(15) bond length is 1.64 Å. The Se(1)-O(7) bond length is 1.73 Å. In the second Se site, Se(2) is bonded to one O(12), one O(14), one O(16), and one O(8) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, and corners with two equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. The Se(2)-O(12) bond length is 1.65 Å. The Se(2)-O(14) bond length is 1.75 Å. The Se(2)-O(16) bond length is 1.65 Å. The Se(2)-O(8) bond length is 1.68 Å. In the third Se site, Se(3) is bonded to one O(1), one O(3), one O(5), and one O(9) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra, and corners with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-54°. The Se(3)-O(1) bond length is 1.65 Å. The Se(3)-O(3) bond length is 1.66 Å. The Se(3)-O(5) bond length is 1.76 Å. The Se(3)-O(9) bond length is 1.66 Å. In the fourth Se site, Se(4) is bonded to one O(10), one O(2), one O(4), and one O(6) atom to form SeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra, and corners with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-54°. The Se(4)-O(10) bond length is 1.66 Å. The Se(4)-O(2) bond length is 1.65 Å. The Se(4)-O(4) bond length is 1.67 Å. The Se(4)-O(6) bond length is 1.76 Å. There are sixteen 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(3) 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(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(3), one H(4), and one Se(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(3), one H(3), and one Se(4) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one H(1) and one Se(3) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one H(2) and one Se(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(3), one H(5), and one Se(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(3), one H(5), and one Se(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(1), one H(2), and one Se(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Na(2), one H(1), and one Se(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one Se(2) atom. In the thirteenth O site, O(13) is bonded in a water-like geometry to one H(3) and one Se(1) atom. In the fourteenth O site, O(14) is bonded in a water-like geometry to one H(4) and one Se(2) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Na(2), one Na(3), and one Se(1) atom. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Na(1), one Na(3), and one Se(2) atom.