Ba6Mn5O16 crystallizes in the orthorhombic Cmce space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to one O(6), three equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(5), and three equivalent O(4) atoms. In the third Ba site, Ba(3) is bonded in a 11-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(5), and three equivalent O(6) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form face-sharing MnO6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form face-sharing MnO6 octahedra. In the third Mn site, Mn(3) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are six inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to one Ba(3), three equivalent Ba(2), one Mn(1), and one Mn(3) atom. In the second O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Mn(3) atoms. In the third O site, O(6) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), three equivalent Ba(3), and one Mn(3) atom. In the fourth O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Mn(1), and one Mn(3) atom. In the fifth O site, O(3) is bonded in a 2-coordinate geometry to one Ba(3), three equivalent Ba(1), one Mn(1), and one Mn(2) atom. In the sixth O site, O(2) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Mn(1), and one Mn(2) atom.
Ba6Mn5O16 crystallizes in the orthorhombic Cmce space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to one O(6), three equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. The Ba(1)-O(6) bond length is 3.33 Å. There is one shorter (2.82 Å) and two longer (2.89 Å) Ba(1)-O(3) bond lengths. There are two shorter (2.85 Å) and two longer (3.34 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.87 Å) and two longer (2.92 Å) Ba(1)-O(2) bond lengths. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(5), and three equivalent O(4) atoms. The Ba(2)-O(6) bond length is 2.67 Å. Both Ba(2)-O(1) bond lengths are 2.77 Å. Both Ba(2)-O(2) bond lengths are 2.85 Å. Both Ba(2)-O(5) bond lengths are 2.87 Å. There is one shorter (2.77 Å) and two longer (2.87 Å) Ba(2)-O(4) bond lengths. In the third Ba site, Ba(3) is bonded in a 11-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(5), and three equivalent O(6) atoms. The Ba(3)-O(3) bond length is 3.22 Å. The Ba(3)-O(4) bond length is 2.84 Å. Both Ba(3)-O(1) bond lengths are 2.76 Å. Both Ba(3)-O(2) bond lengths are 2.93 Å. Both Ba(3)-O(5) bond lengths are 2.93 Å. There are two shorter (2.91 Å) and one longer (3.09 Å) Ba(3)-O(6) bond length. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form face-sharing MnO6 octahedra. The Mn(1)-O(3) bond length is 1.94 Å. The Mn(1)-O(4) bond length is 1.87 Å. Both Mn(1)-O(1) bond lengths are 1.88 Å. Both Mn(1)-O(2) bond lengths are 1.93 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form face-sharing MnO6 octahedra. Both Mn(2)-O(3) bond lengths are 1.91 Å. All Mn(2)-O(2) bond lengths are 1.90 Å. In the third Mn site, Mn(3) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 8°. The Mn(3)-O(4) bond length is 2.11 Å. The Mn(3)-O(6) bond length is 1.79 Å. Both Mn(3)-O(1) bond lengths are 1.95 Å. Both Mn(3)-O(5) bond lengths are 1.89 Å. There are six inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to one Ba(3), three equivalent Ba(2), one Mn(1), and one Mn(3) atom. In the second O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Mn(3) atoms. In the third O site, O(6) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), three equivalent Ba(3), and one Mn(3) atom. In the fourth O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Mn(1), and one Mn(3) atom. In the fifth O site, O(3) is bonded in a 2-coordinate geometry to one Ba(3), three equivalent Ba(1), one Mn(1), and one Mn(2) atom. In the sixth O site, O(2) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Mn(1), and one Mn(2) atom.