NaMn7O12 crystallizes in the cubic Im-3 space group. Na(1) is bonded to twelve equivalent O(1) atoms to form NaO12 cuboctahedra that share faces with eight equivalent Mn(1)O6 octahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to six equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. In the second Mn site, Mn(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. O(1) is bonded in a 3-coordinate geometry to one Na(1), one Mn(2), and two equivalent Mn(1) atoms.
NaMn7O12 crystallizes in the cubic Im-3 space group. Na(1) is bonded to twelve equivalent O(1) atoms to form NaO12 cuboctahedra that share faces with eight equivalent Mn(1)O6 octahedra. All Na(1)-O(1) bond lengths are 2.72 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to six equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. All Mn(1)-O(1) bond lengths are 1.98 Å. In the second Mn site, Mn(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All Mn(2)-O(1) bond lengths are 1.95 Å. O(1) is bonded in a 3-coordinate geometry to one Na(1), one Mn(2), and two equivalent Mn(1) atoms.