KSe crystallizes in the orthorhombic Pbca space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent K(2), three equivalent Se(1), and three equivalent Se(2) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent K(1), three equivalent Se(1), and three equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent K(1), three equivalent K(2), and one Se(1) atom to form a mixture of distorted face and edge-sharing SeK6Se pentagonal bipyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent K(1) and three equivalent K(2) atoms.
KSe crystallizes in the orthorhombic Pbca space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent K(2), three equivalent Se(1), and three equivalent Se(2) atoms. Both K(1)-K(2) bond lengths are 3.27 Å. There are a spread of K(1)-Se(1) bond distances ranging from 3.26-3.40 Å. There are a spread of K(1)-Se(2) bond distances ranging from 3.23-3.75 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent K(1), three equivalent Se(1), and three equivalent Se(2) atoms. There are a spread of K(2)-Se(1) bond distances ranging from 3.28-3.42 Å. There are a spread of K(2)-Se(2) bond distances ranging from 3.25-3.70 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent K(1), three equivalent K(2), and one Se(1) atom to form a mixture of distorted face and edge-sharing SeK6Se pentagonal bipyramids. The Se(1)-Se(1) bond length is 2.44 Å. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent K(1) and three equivalent K(2) atoms.