Ba2MgMo4(Se2O11)2 crystallizes in the monoclinic Cm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(6), two equivalent O(7), and two equivalent O(9) atoms. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Mg(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(6) atoms. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(10), one O(2), one O(3), one O(4), one O(5), and one O(9) atom to form distorted corner-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the second Mo site, Mo(2) is bonded to one O(1), one O(11), one O(12), one O(6), one O(7), and one O(8) atom to form distorted corner-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(4), and one O(7) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(12), one O(3), and one O(8) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ba(2) and one Mo(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Mo(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(2), one Mg(1), one Mo(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Mo(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(2) and one Mo(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Mo(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ba(1), one Mo(2), and one Se(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mo(2) and one Se(2) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ba(1) and one Mo(1) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mo(1) and one Se(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to two equivalent Mo(2) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Mo(2) and one Se(2) atom.
Ba2MgMo4(Se2O11)2 crystallizes in the monoclinic Cm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(6), two equivalent O(7), and two equivalent O(9) atoms. Both Ba(1)-O(6) bond lengths are 2.88 Å. Both Ba(1)-O(7) bond lengths are 2.86 Å. Both Ba(1)-O(9) bond lengths are 2.79 Å. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Both Ba(2)-O(1) bond lengths are 2.58 Å. Both Ba(2)-O(3) bond lengths are 2.92 Å. Both Ba(2)-O(5) bond lengths are 2.73 Å. Mg(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(6) atoms. The Mg(1)-O(2) bond length is 2.06 Å. Both Mg(1)-O(3) bond lengths are 2.22 Å. Both Mg(1)-O(6) bond lengths are 2.04 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(10), one O(2), one O(3), one O(4), one O(5), and one O(9) atom to form distorted corner-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 57°. The Mo(1)-O(10) bond length is 1.96 Å. The Mo(1)-O(2) bond length is 2.00 Å. The Mo(1)-O(3) bond length is 2.28 Å. The Mo(1)-O(4) bond length is 2.28 Å. The Mo(1)-O(5) bond length is 1.75 Å. The Mo(1)-O(9) bond length is 1.76 Å. In the second Mo site, Mo(2) is bonded to one O(1), one O(11), one O(12), one O(6), one O(7), and one O(8) atom to form distorted corner-sharing MoO6 octahedra. The corner-sharing octahedral tilt angles are 53°. The Mo(2)-O(1) bond length is 1.78 Å. The Mo(2)-O(11) bond length is 1.97 Å. The Mo(2)-O(12) bond length is 2.21 Å. The Mo(2)-O(6) bond length is 1.87 Å. The Mo(2)-O(7) bond length is 2.27 Å. The Mo(2)-O(8) bond length is 2.20 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(4), and one O(7) atom. The Se(1)-O(10) bond length is 1.85 Å. The Se(1)-O(4) bond length is 1.70 Å. The Se(1)-O(7) bond length is 1.72 Å. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(12), one O(3), and one O(8) atom. The Se(2)-O(12) bond length is 1.73 Å. The Se(2)-O(3) bond length is 1.79 Å. The Se(2)-O(8) bond length is 1.71 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ba(2) and one Mo(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Mo(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(2), one Mg(1), one Mo(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Mo(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(2) and one Mo(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Mo(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ba(1), one Mo(2), and one Se(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Mo(2) and one Se(2) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ba(1) and one Mo(1) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mo(1) and one Se(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to two equivalent Mo(2) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Mo(2) and one Se(2) atom.