BaMgSiO4 crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to three equivalent O(1) and six equivalent O(3) atoms. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(4) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form MgO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Mg(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(3), one Mg(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(2), one Mg(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(3), one Mg(1), and one Si(1) atom.
BaMgSiO4 crystallizes in the hexagonal P6_3 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. All Ba(1)-O(1) bond lengths are 2.76 Å. All Ba(1)-O(2) bond lengths are 2.98 Å. All Ba(1)-O(4) bond lengths are 3.16 Å. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to three equivalent O(1) and six equivalent O(3) atoms. All Ba(2)-O(1) bond lengths are 3.01 Å. There are three shorter (2.81 Å) and three longer (3.04 Å) Ba(2)-O(3) bond lengths. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(4) atoms. All Ba(3)-O(2) bond lengths are 2.83 Å. All Ba(3)-O(4) bond lengths are 2.75 Å. Mg(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form MgO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. The Mg(1)-O(1) bond length is 1.94 Å. The Mg(1)-O(2) bond length is 1.96 Å. The Mg(1)-O(3) bond length is 1.96 Å. The Mg(1)-O(4) bond length is 1.96 Å. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Mg(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.65 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(4) bond length is 1.65 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(3), one Mg(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(2), one Mg(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(3), one Mg(1), and one Si(1) atom.