MgSn8(P2O9)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(9) atoms. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in an L-shaped geometry to one O(3) and one O(8) atom. In the second Sn site, Sn(2) is bonded in a 2-coordinate geometry to one O(1) and one O(9) atom. In the third Sn site, Sn(3) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(9) atom. In the fourth Sn site, Sn(4) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(6), and one O(7) atom. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(1), one O(4), one O(5), and one O(8) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(3), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(3) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sn(4) and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Sn(2), and one Sn(3) atom.
MgSn8(P2O9)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(9) atoms. Both Mg(1)-O(1) bond lengths are 2.31 Å. Both Mg(1)-O(2) bond lengths are 2.43 Å. Both Mg(1)-O(9) bond lengths are 2.01 Å. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in an L-shaped geometry to one O(3) and one O(8) atom. The Sn(1)-O(3) bond length is 2.13 Å. The Sn(1)-O(8) bond length is 2.14 Å. In the second Sn site, Sn(2) is bonded in a 2-coordinate geometry to one O(1) and one O(9) atom. The Sn(2)-O(1) bond length is 2.30 Å. The Sn(2)-O(9) bond length is 2.08 Å. In the third Sn site, Sn(3) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(9) atom. The Sn(3)-O(2) bond length is 2.22 Å. The Sn(3)-O(4) bond length is 2.17 Å. The Sn(3)-O(9) bond length is 2.12 Å. In the fourth Sn site, Sn(4) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(7) atom. The Sn(4)-O(5) bond length is 2.12 Å. The Sn(4)-O(6) bond length is 2.20 Å. The Sn(4)-O(7) bond length is 2.15 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(6), and one O(7) atom. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.56 Å. The P(1)-O(7) bond length is 1.55 Å. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(1), one O(4), one O(5), and one O(8) atom. The P(2)-O(1) bond length is 1.58 Å. The P(2)-O(4) bond length is 1.54 Å. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(8) bond length is 1.56 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(3), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(3) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sn(4) and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Sn(2), and one Sn(3) atom.