KMn4O8 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a hexagonal planar geometry to two equivalent O(2) and four equivalent O(3) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing MnO6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form edge-sharing MnO6 octahedra. In the third Mn site, Mn(3) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form edge-sharing MnO6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(2) and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Mn(3), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one Mn(1), one Mn(2), and one Mn(3) atom.
KMn4O8 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a hexagonal planar geometry to two equivalent O(2) and four equivalent O(3) atoms. Both K(1)-O(2) bond lengths are 2.76 Å. All K(1)-O(3) bond lengths are 2.85 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing MnO6 octahedra. Both Mn(1)-O(1) bond lengths are 1.97 Å. Both Mn(1)-O(2) bond lengths are 1.92 Å. Both Mn(1)-O(3) bond lengths are 1.96 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form edge-sharing MnO6 octahedra. Both Mn(2)-O(1) bond lengths are 1.97 Å. All Mn(2)-O(3) bond lengths are 1.94 Å. In the third Mn site, Mn(3) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form edge-sharing MnO6 octahedra. Both Mn(3)-O(2) bond lengths are 2.17 Å. All Mn(3)-O(3) bond lengths are 1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(2) and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Mn(3), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one Mn(1), one Mn(2), and one Mn(3) atom.