CaMn4O8 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form edge-sharing MnO6 octahedra. In the second Mn site, Mn(2) is bonded to six equivalent O(1) atoms to form edge-sharing MnO6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Ca(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Mn(1) atoms.
CaMn4O8 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. All Ca(1)-O(1) bond lengths are 2.39 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form edge-sharing MnO6 octahedra. Both Mn(1)-O(2) bond lengths are 1.99 Å. All Mn(1)-O(1) bond lengths are 1.95 Å. In the second Mn site, Mn(2) is bonded to six equivalent O(1) atoms to form edge-sharing MnO6 octahedra. All Mn(2)-O(1) bond lengths are 2.14 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Ca(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Mn(1) atoms.