Ba2MgO3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(2), and three equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(1), and three equivalent O(2) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing MgO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(2), three equivalent Ba(1), and one Mg(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ba(1), three equivalent Ba(2), and one Mg(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Mg(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Mg(1) atoms.
Ba2MgO3 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(2), and three equivalent O(1) atoms. The Ba(1)-O(3) bond length is 2.79 Å. The Ba(1)-O(4) bond length is 2.89 Å. There is one shorter (2.68 Å) and one longer (2.77 Å) Ba(1)-O(2) bond length. There are a spread of Ba(1)-O(1) bond distances ranging from 2.80-3.26 Å. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(1), and three equivalent O(2) atoms. The Ba(2)-O(3) bond length is 3.02 Å. The Ba(2)-O(4) bond length is 3.02 Å. There is one shorter (2.67 Å) and one longer (2.70 Å) Ba(2)-O(1) bond length. There are a spread of Ba(2)-O(2) bond distances ranging from 2.66-3.41 Å. Mg(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing MgO4 tetrahedra. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(2) bond length is 2.02 Å. The Mg(1)-O(3) bond length is 2.02 Å. The Mg(1)-O(4) bond length is 1.96 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(2), three equivalent Ba(1), and one Mg(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ba(1), three equivalent Ba(2), and one Mg(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Mg(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Mg(1) atoms.