Mg2TaMnO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and four equivalent O(4) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-46°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), and two equivalent Ta(1) atoms to form distorted OMg2Ta2 trigonal pyramids that share corners with two equivalent O(2)Mg2Mn2 tetrahedra and corners with two equivalent O(1)Mg2Ta2 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and two equivalent Mn(1) atoms to form OMg2Mn2 tetrahedra that share corners with two equivalent O(2)Mg2Mn2 tetrahedra and corners with two equivalent O(1)Mg2Ta2 trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Mg(1), one Ta(1), and one Mn(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Ta(1), and one Mn(1) atom.
Mg2TaMnO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(4), and four equivalent O(3) atoms. The Mg(1)-O(1) bond length is 2.39 Å. The Mg(1)-O(2) bond length is 2.09 Å. Both Mg(1)-O(4) bond lengths are 2.46 Å. There are two shorter (2.09 Å) and two longer (2.69 Å) Mg(1)-O(3) bond lengths. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and four equivalent O(4) atoms. The Mg(2)-O(1) bond length is 2.05 Å. The Mg(2)-O(2) bond length is 2.09 Å. There are two shorter (2.06 Å) and two longer (2.67 Å) Mg(2)-O(4) bond lengths. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. Both Ta(1)-O(1) bond lengths are 2.03 Å. Both Ta(1)-O(3) bond lengths are 1.99 Å. Both Ta(1)-O(4) bond lengths are 1.96 Å. Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-46°. Both Mn(1)-O(2) bond lengths are 2.04 Å. Both Mn(1)-O(3) bond lengths are 1.94 Å. Both Mn(1)-O(4) bond lengths are 2.25 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), and two equivalent Ta(1) atoms to form distorted OMg2Ta2 trigonal pyramids that share corners with two equivalent O(2)Mg2Mn2 tetrahedra and corners with two equivalent O(1)Mg2Ta2 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and two equivalent Mn(1) atoms to form OMg2Mn2 tetrahedra that share corners with two equivalent O(2)Mg2Mn2 tetrahedra and corners with two equivalent O(1)Mg2Ta2 trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Mg(1), one Ta(1), and one Mn(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Ta(1), and one Mn(1) atom.