Ba(MnO4)2 crystallizes in the orthorhombic Fddd space group. Ba(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing MnO6 octahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted L-shaped geometry to one Ba(1) and two equivalent Mn(1) atoms. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one Mn(1) atom.
Ba(MnO4)2 crystallizes in the orthorhombic Fddd space group. Ba(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 2.80 Å. All Ba(1)-O(2) bond lengths are 2.81 Å. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing MnO6 octahedra. Both Mn(1)-O(1) bond lengths are 1.87 Å. There are two shorter (1.89 Å) and two longer (1.90 Å) Mn(1)-O(2) bond lengths. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted L-shaped geometry to one Ba(1) and two equivalent Mn(1) atoms. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one Mn(1) atom.