K4N2O5 crystallizes in the monoclinic C2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one N(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second K site, K(2) is bonded in a 5-coordinate geometry to one N(1), one O(2), one O(3), and two equivalent O(1) atoms. N(1) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one O(1), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent K(1), two equivalent K(2), and one N(1) atom. In the second O site, O(2) is bonded to two equivalent K(2) and four equivalent K(1) atoms to form corner-sharing OK6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one N(1) atom.
K4N2O5 crystallizes in the monoclinic C2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one N(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms. The K(1)-N(1) bond length is 3.01 Å. The K(1)-O(3) bond length is 2.77 Å. There is one shorter (2.81 Å) and one longer (3.19 Å) K(1)-O(1) bond length. There is one shorter (2.67 Å) and one longer (2.82 Å) K(1)-O(2) bond length. In the second K site, K(2) is bonded in a 5-coordinate geometry to one N(1), one O(2), one O(3), and two equivalent O(1) atoms. The K(2)-N(1) bond length is 3.17 Å. The K(2)-O(2) bond length is 2.47 Å. The K(2)-O(3) bond length is 2.86 Å. There is one shorter (2.76 Å) and one longer (2.91 Å) K(2)-O(1) bond length. N(1) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one O(1), and one O(3) atom. The N(1)-O(1) bond length is 1.28 Å. The N(1)-O(3) bond length is 1.27 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent K(1), two equivalent K(2), and one N(1) atom. In the second O site, O(2) is bonded to two equivalent K(2) and four equivalent K(1) atoms to form corner-sharing OK6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one N(1) atom.