KSm(SeO4)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(7), one O(8), two equivalent O(6), and three equivalent O(3) atoms. Sm(1) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(8), two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second Se site, Se(2) is bonded in a tetrahedral geometry to one O(4), one O(5), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one Se(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent K(1) and one Se(2) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one K(1), two equivalent Sm(1), and one Se(1) atom. In the fourth O site, O(8) is bonded in a 3-coordinate geometry to one K(1), one Sm(1), and one Se(2) atom. In the fifth O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Sm(1), and one Se(1) atom. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Sm(1) and one Se(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Se(1) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to one K(1), one Sm(1), and one Se(2) atom.
KSm(SeO4)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(7), one O(8), two equivalent O(6), and three equivalent O(3) atoms. The K(1)-O(1) bond length is 3.08 Å. The K(1)-O(4) bond length is 2.83 Å. The K(1)-O(7) bond length is 3.14 Å. The K(1)-O(8) bond length is 3.01 Å. There is one shorter (2.80 Å) and one longer (2.82 Å) K(1)-O(6) bond length. There are a spread of K(1)-O(3) bond distances ranging from 2.85-3.11 Å. Sm(1) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(8), two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms. The Sm(1)-O(1) bond length is 2.42 Å. The Sm(1)-O(4) bond length is 2.50 Å. The Sm(1)-O(8) bond length is 2.45 Å. There is one shorter (2.52 Å) and one longer (2.54 Å) Sm(1)-O(2) bond length. There is one shorter (2.45 Å) and one longer (2.50 Å) Sm(1)-O(5) bond length. There is one shorter (2.57 Å) and one longer (2.70 Å) Sm(1)-O(7) bond length. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(7) atom. The Se(1)-O(1) bond length is 1.67 Å. The Se(1)-O(2) bond length is 1.71 Å. The Se(1)-O(3) bond length is 1.64 Å. The Se(1)-O(7) bond length is 1.71 Å. In the second Se site, Se(2) is bonded in a tetrahedral geometry to one O(4), one O(5), one O(6), and one O(8) atom. The Se(2)-O(4) bond length is 1.68 Å. The Se(2)-O(5) bond length is 1.70 Å. The Se(2)-O(6) bond length is 1.64 Å. The Se(2)-O(8) bond length is 1.68 Å. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one Se(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent K(1) and one Se(2) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one K(1), two equivalent Sm(1), and one Se(1) atom. In the fourth O site, O(8) is bonded in a 3-coordinate geometry to one K(1), one Sm(1), and one Se(2) atom. In the fifth O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Sm(1), and one Se(1) atom. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Sm(1) and one Se(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Se(1) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to one K(1), one Sm(1), and one Se(2) atom.