Ba6Mg(P2O7)3 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. In the fourth Ba site, Ba(4) is bonded in a 8-coordinate geometry to four equivalent O(3) and four equivalent O(4) atoms. Mg(1) is bonded in an L-shaped geometry to two equivalent O(5) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(5), one O(7), and two equivalent O(4) atoms to form corner-sharing PO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), one Ba(4), and one P(2) atom. In the second O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(3), one Mg(1), and one P(2) atom. In the third O site, O(6) is bonded in a bent 150 degrees geometry to one Ba(3) and two equivalent P(1) atoms. In the fourth O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent P(2) atoms. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to one Ba(3), two equivalent Ba(1), and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(4), and one P(1) atom.
Ba6Mg(P2O7)3 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. Both Ba(1)-O(2) bond lengths are 3.12 Å. Both Ba(1)-O(3) bond lengths are 3.01 Å. Both Ba(1)-O(4) bond lengths are 2.96 Å. There are two shorter (2.91 Å) and two longer (2.95 Å) Ba(1)-O(1) bond lengths. In the second Ba site, Ba(2) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. All Ba(2)-O(3) bond lengths are 2.82 Å. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. The Ba(3)-O(6) bond length is 2.90 Å. Both Ba(3)-O(1) bond lengths are 2.75 Å. Both Ba(3)-O(2) bond lengths are 2.73 Å. Both Ba(3)-O(4) bond lengths are 2.90 Å. Both Ba(3)-O(5) bond lengths are 3.05 Å. In the fourth Ba site, Ba(4) is bonded in a 8-coordinate geometry to four equivalent O(3) and four equivalent O(4) atoms. All Ba(4)-O(3) bond lengths are 2.91 Å. All Ba(4)-O(4) bond lengths are 3.04 Å. Mg(1) is bonded in an L-shaped geometry to two equivalent O(5) atoms. Both Mg(1)-O(5) bond lengths are 2.09 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form corner-sharing PO4 tetrahedra. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(6) bond length is 1.65 Å. In the second P site, P(2) is bonded to one O(5), one O(7), and two equivalent O(4) atoms to form corner-sharing PO4 tetrahedra. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.62 Å. Both P(2)-O(4) bond lengths are 1.53 Å. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), one Ba(4), and one P(2) atom. In the second O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(3), one Mg(1), and one P(2) atom. In the third O site, O(6) is bonded in a bent 150 degrees geometry to one Ba(3) and two equivalent P(1) atoms. In the fourth O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent P(2) atoms. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to one Ba(3), two equivalent Ba(1), and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(4), and one P(1) atom.