KNi2H3(SeO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, and edges with two equivalent Ni(2)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) atom. In the third H site, H(3) is bonded in a linear geometry to one O(3) and one O(4) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(5), one O(7), and one O(8) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the second Se site, Se(2) is bonded to one O(10), one O(2), one O(6), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one K(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one K(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to one Ni(1), one Ni(2), one H(1), and one H(3) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Ni(1), one Ni(2), one H(2), and one H(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), one Ni(2), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), one Ni(2), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(2), and one Se(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(1), and one Se(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(2), and one Se(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(1), and one Se(2) atom.
KNi2H3(SeO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The K(1)-O(1) bond length is 2.74 Å. The K(1)-O(10) bond length is 2.75 Å. The K(1)-O(2) bond length is 2.75 Å. The K(1)-O(5) bond length is 3.03 Å. The K(1)-O(6) bond length is 3.02 Å. The K(1)-O(7) bond length is 2.76 Å. The K(1)-O(8) bond length is 2.76 Å. The K(1)-O(9) bond length is 2.75 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, and edges with two equivalent Ni(2)O6 octahedra. The Ni(1)-O(10) bond length is 2.07 Å. The Ni(1)-O(3) bond length is 2.03 Å. The Ni(1)-O(4) bond length is 2.10 Å. The Ni(1)-O(5) bond length is 2.18 Å. The Ni(1)-O(6) bond length is 2.18 Å. The Ni(1)-O(8) bond length is 2.07 Å. In the second Ni site, Ni(2) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra, corners with two equivalent Se(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. The Ni(2)-O(3) bond length is 2.03 Å. The Ni(2)-O(4) bond length is 2.10 Å. The Ni(2)-O(5) bond length is 2.18 Å. The Ni(2)-O(6) bond length is 2.18 Å. The Ni(2)-O(7) bond length is 2.06 Å. The Ni(2)-O(9) bond length is 2.07 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.98 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 0.98 Å. In the third H site, H(3) is bonded in a linear geometry to one O(3) and one O(4) atom. The H(3)-O(3) bond length is 1.41 Å. The H(3)-O(4) bond length is 1.10 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(5), one O(7), and one O(8) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. The Se(1)-O(1) bond length is 1.64 Å. The Se(1)-O(5) bond length is 1.72 Å. The Se(1)-O(7) bond length is 1.68 Å. The Se(1)-O(8) bond length is 1.68 Å. In the second Se site, Se(2) is bonded to one O(10), one O(2), one O(6), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. The Se(2)-O(10) bond length is 1.68 Å. The Se(2)-O(2) bond length is 1.65 Å. The Se(2)-O(6) bond length is 1.72 Å. The Se(2)-O(9) bond length is 1.68 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one K(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one K(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to one Ni(1), one Ni(2), one H(1), and one H(3) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Ni(1), one Ni(2), one H(2), and one H(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), one Ni(2), and one Se(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), one Ni(2), and one Se(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(2), and one Se(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(1), and one Se(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(2), and one Se(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one K(1), one Ni(1), and one Se(2) atom.