Na4PH5Se3O16 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(12), one O(15), one O(2), one O(3), and one O(7) atom to form NaO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra,  an edgeedge with one Na(4)O6 octahedra, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(4), one O(5), one O(6), and one O(8) atom. In the third Na site, Na(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(15), one O(4), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Se(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Na(4)O6 octahedra. In the fourth Na site, Na(4) is bonded to one O(10), one O(14), one O(15), one O(16), one O(2), and one O(5) atom to form NaO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. P(1) is bonded to one O(11), one O(12), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 51-54°. There are five inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(3) and one O(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) and one O(7) atom. In the third H site, H(3) is bonded in a linear geometry to one O(8) and one O(9) atom. In the fourth H site, H(4) is bonded in a linear geometry to one O(11) and one O(14) atom. In the fifth H site, H(5) is bonded in a linear geometry to one O(1) and one O(16) atom. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(15), one O(16), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-60°. In the second Se site, Se(2) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Na(4)O6 octahedra and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 52-60°. In the third Se site, Se(3) is bonded to one O(1), one O(13), one O(14), and one O(2) atom to form SeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, and  a cornercorner with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 45-64°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one H(5), and one Se(3) atom. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(4), and one Se(3) atom to form distorted edge-sharing ONa3Se tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one H(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2), one Na(3), and one Se(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one H(2), and one Se(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Na(2), one H(1), and one Se(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(1), one P(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(2), one P(1), and one H(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(3), one H(3), and one Se(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(3), one Na(4), and one Se(2) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Na(3), one P(1), and one H(4) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(3), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(2), one Na(3), and one Se(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Na(4), one H(4), and one Se(3) atom. In the fifteenth O site, O(15) is bonded to one Na(1), one Na(3), one Na(4), and one Se(1) atom to form distorted edge-sharing ONa3Se trigonal pyramids. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Na(4), one H(5), and one Se(1) atom.
Na4PH5Se3O16 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(12), one O(15), one O(2), one O(3), and one O(7) atom to form NaO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra,  an edgeedge with one Na(4)O6 octahedra, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. The Na(1)-O(1) bond length is 2.43 Å. The Na(1)-O(12) bond length is 2.35 Å. The Na(1)-O(15) bond length is 2.51 Å. The Na(1)-O(2) bond length is 2.67 Å. The Na(1)-O(3) bond length is 2.47 Å. The Na(1)-O(7) bond length is 2.60 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(4), one O(5), one O(6), and one O(8) atom. The Na(2)-O(13) bond length is 2.50 Å. The Na(2)-O(2) bond length is 2.46 Å. The Na(2)-O(4) bond length is 2.54 Å. The Na(2)-O(5) bond length is 2.49 Å. The Na(2)-O(6) bond length is 2.63 Å. The Na(2)-O(8) bond length is 2.34 Å. In the third Na site, Na(3) is bonded to one O(10), one O(11), one O(12), one O(13), one O(15), one O(4), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Se(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Na(4)O6 octahedra. The Na(3)-O(10) bond length is 2.69 Å. The Na(3)-O(11) bond length is 2.75 Å. The Na(3)-O(12) bond length is 2.35 Å. The Na(3)-O(13) bond length is 2.68 Å. The Na(3)-O(15) bond length is 2.48 Å. The Na(3)-O(4) bond length is 2.47 Å. The Na(3)-O(9) bond length is 2.45 Å. In the fourth Na site, Na(4) is bonded to one O(10), one O(14), one O(15), one O(16), one O(2), and one O(5) atom to form NaO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, corners with two equivalent Se(3)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Na(3)O7 pentagonal bipyramid. The Na(4)-O(10) bond length is 2.35 Å. The Na(4)-O(14) bond length is 2.49 Å. The Na(4)-O(15) bond length is 2.58 Å. The Na(4)-O(16) bond length is 2.49 Å. The Na(4)-O(2) bond length is 2.50 Å. The Na(4)-O(5) bond length is 2.55 Å. P(1) is bonded to one O(11), one O(12), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 51-54°. The P(1)-O(11) bond length is 1.58 Å. The P(1)-O(12) bond length is 1.49 Å. The P(1)-O(7) bond length is 1.60 Å. The P(1)-O(8) bond length is 1.57 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(3) and one O(6) atom. The H(1)-O(3) bond length is 1.57 Å. The H(1)-O(6) bond length is 1.03 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) and one O(7) atom. The H(2)-O(5) bond length is 1.71 Å. The H(2)-O(7) bond length is 1.01 Å. In the third H site, H(3) is bonded in a linear geometry to one O(8) and one O(9) atom. The H(3)-O(8) bond length is 1.03 Å. The H(3)-O(9) bond length is 1.51 Å. In the fourth H site, H(4) is bonded in a linear geometry to one O(11) and one O(14) atom. The H(4)-O(11) bond length is 1.03 Å. The H(4)-O(14) bond length is 1.54 Å. In the fifth H site, H(5) is bonded in a linear geometry to one O(1) and one O(16) atom. The H(5)-O(1) bond length is 1.42 Å. The H(5)-O(16) bond length is 1.09 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(15), one O(16), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-60°. The Se(1)-O(15) bond length is 1.67 Å. The Se(1)-O(16) bond length is 1.75 Å. The Se(1)-O(3) bond length is 1.67 Å. The Se(1)-O(4) bond length is 1.65 Å. In the second Se site, Se(2) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Na(4)O6 octahedra and corners with two equivalent Na(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 52-60°. The Se(2)-O(10) bond length is 1.63 Å. The Se(2)-O(5) bond length is 1.68 Å. The Se(2)-O(6) bond length is 1.76 Å. The Se(2)-O(9) bond length is 1.66 Å. In the third Se site, Se(3) is bonded to one O(1), one O(13), one O(14), and one O(2) atom to form SeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, and  a cornercorner with one Na(3)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 45-64°. The Se(3)-O(1) bond length is 1.70 Å. The Se(3)-O(13) bond length is 1.66 Å. The Se(3)-O(14) bond length is 1.68 Å. The Se(3)-O(2) bond length is 1.68 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one H(5), and one Se(3) atom. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(4), and one Se(3) atom to form distorted edge-sharing ONa3Se tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one H(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2), one Na(3), and one Se(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one H(2), and one Se(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Na(2), one H(1), and one Se(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(1), one P(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(2), one P(1), and one H(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(3), one H(3), and one Se(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(3), one Na(4), and one Se(2) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Na(3), one P(1), and one H(4) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(3), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(2), one Na(3), and one Se(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Na(4), one H(4), and one Se(3) atom. In the fifteenth O site, O(15) is bonded to one Na(1), one Na(3), one Na(4), and one Se(1) atom to form distorted edge-sharing ONa3Se trigonal pyramids. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Na(4), one H(5), and one Se(1) atom.