K2SeMoO6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(5), two equivalent O(6), and three equivalent O(2) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms. Mo(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(4), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one K(2), and one Se(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2), three equivalent K(1), and one Mo(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent K(2) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(1), and one Se(1) atom. In the fifth O site, O(5) is bonded in a 1-coordinate geometry to two equivalent K(1) and two equivalent Mo(1) atoms. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Mo(1), and one Se(1) atom.
K2SeMoO6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(5), two equivalent O(6), and three equivalent O(2) atoms. The K(1)-O(1) bond length is 2.68 Å. There is one shorter (2.70 Å) and one longer (3.22 Å) K(1)-O(5) bond length. There is one shorter (2.76 Å) and one longer (3.00 Å) K(1)-O(6) bond length. There is one shorter (2.72 Å) and two longer (3.09 Å) K(1)-O(2) bond lengths. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms. The K(2)-O(1) bond length is 2.93 Å. The K(2)-O(2) bond length is 2.71 Å. The K(2)-O(6) bond length is 3.22 Å. There is one shorter (2.71 Å) and one longer (2.83 Å) K(2)-O(3) bond length. Both K(2)-O(4) bond lengths are 2.84 Å. Mo(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. The Mo(1)-O(2) bond length is 1.74 Å. The Mo(1)-O(3) bond length is 1.73 Å. The Mo(1)-O(4) bond length is 2.17 Å. The Mo(1)-O(6) bond length is 2.13 Å. There is one shorter (1.78 Å) and one longer (2.37 Å) Mo(1)-O(5) bond length. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(4), and one O(6) atom. The Se(1)-O(1) bond length is 1.66 Å. The Se(1)-O(4) bond length is 1.74 Å. The Se(1)-O(6) bond length is 1.75 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one K(2), and one Se(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2), three equivalent K(1), and one Mo(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent K(2) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(1), and one Se(1) atom. In the fifth O site, O(5) is bonded in a 1-coordinate geometry to two equivalent K(1) and two equivalent Mo(1) atoms. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Mo(1), and one Se(1) atom.