Y2Mn3O9 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(6), two equivalent O(3), and two equivalent O(5) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), one O(7), one O(8), and two equivalent O(9) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 3-11°. In the second Mn site, Mn(2) is bonded to one O(2), one O(5), one O(7), one O(9), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. In the third Mn site, Mn(3) is bonded to one O(1), one O(6), one O(8), one O(9), and two equivalent O(7) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a distorted square co-planar geometry to one Mn(1), one Mn(2), and two equivalent Mn(3) atoms. In the second O site, O(8) is bonded in a distorted square co-planar geometry to one Mn(1), one Mn(3), and two equivalent Mn(2) atoms. In the third O site, O(9) is bonded in a distorted square co-planar geometry to one Mn(2), one Mn(3), and two equivalent Mn(1) atoms. In the fourth O site, O(1) is bonded in a trigonal planar geometry to two equivalent Y(1) and one Mn(3) atom. In the fifth O site, O(2) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Mn(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Mn(1) atom. In the seventh O site, O(4) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(2), and one Mn(1) atom. In the eighth O site, O(5) is bonded in a trigonal planar geometry to two equivalent Y(2) and one Mn(2) atom. In the ninth O site, O(6) is bonded to one Y(2), two equivalent Y(1), and one Mn(3) atom to form distorted corner-sharing OY3Mn tetrahedra.
Y2Mn3O9 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms. The Y(1)-O(2) bond length is 2.25 Å. The Y(1)-O(3) bond length is 2.31 Å. The Y(1)-O(4) bond length is 2.31 Å. Both Y(1)-O(1) bond lengths are 2.34 Å. Both Y(1)-O(6) bond lengths are 2.49 Å. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(6), two equivalent O(3), and two equivalent O(5) atoms. The Y(2)-O(2) bond length is 2.21 Å. The Y(2)-O(4) bond length is 2.30 Å. The Y(2)-O(6) bond length is 2.37 Å. Both Y(2)-O(3) bond lengths are 2.56 Å. Both Y(2)-O(5) bond lengths are 2.26 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), one O(7), one O(8), and two equivalent O(9) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 3-11°. The Mn(1)-O(3) bond length is 1.89 Å. The Mn(1)-O(4) bond length is 1.88 Å. The Mn(1)-O(7) bond length is 2.19 Å. The Mn(1)-O(8) bond length is 2.26 Å. Both Mn(1)-O(9) bond lengths are 2.00 Å. In the second Mn site, Mn(2) is bonded to one O(2), one O(5), one O(7), one O(9), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. The Mn(2)-O(2) bond length is 1.87 Å. The Mn(2)-O(5) bond length is 1.83 Å. The Mn(2)-O(7) bond length is 2.32 Å. The Mn(2)-O(9) bond length is 2.02 Å. Both Mn(2)-O(8) bond lengths are 2.00 Å. In the third Mn site, Mn(3) is bonded to one O(1), one O(6), one O(8), one O(9), and two equivalent O(7) atoms to form a mixture of distorted edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. The Mn(3)-O(1) bond length is 1.87 Å. The Mn(3)-O(6) bond length is 1.88 Å. The Mn(3)-O(8) bond length is 2.16 Å. The Mn(3)-O(9) bond length is 2.49 Å. Both Mn(3)-O(7) bond lengths are 2.00 Å. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a distorted square co-planar geometry to one Mn(1), one Mn(2), and two equivalent Mn(3) atoms. In the second O site, O(8) is bonded in a distorted square co-planar geometry to one Mn(1), one Mn(3), and two equivalent Mn(2) atoms. In the third O site, O(9) is bonded in a distorted square co-planar geometry to one Mn(2), one Mn(3), and two equivalent Mn(1) atoms. In the fourth O site, O(1) is bonded in a trigonal planar geometry to two equivalent Y(1) and one Mn(3) atom. In the fifth O site, O(2) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Mn(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Y(1), two equivalent Y(2), and one Mn(1) atom. In the seventh O site, O(4) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(2), and one Mn(1) atom. In the eighth O site, O(5) is bonded in a trigonal planar geometry to two equivalent Y(2) and one Mn(2) atom. In the ninth O site, O(6) is bonded to one Y(2), two equivalent Y(1), and one Mn(3) atom to form distorted corner-sharing OY3Mn tetrahedra.