MgSn8(P2O9)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), and one O(6) atom. There are eight inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted T-shaped geometry to one O(3), one O(8), and one O(9) atom. In the second Sn site, Sn(2) is bonded in an L-shaped geometry to one O(18) and one O(9) atom. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(8), and one O(9) atom. In the fourth Sn site, Sn(4) is bonded in a distorted T-shaped geometry to one O(12), one O(5), and one O(6) atom. In the fifth Sn site, Sn(5) is bonded in a distorted T-shaped geometry to one O(13), one O(14), and one O(7) atom. In the sixth Sn site, Sn(6) is bonded in a 3-coordinate geometry to one O(10), one O(15), and one O(17) atom. In the seventh Sn site, Sn(7) is bonded in an L-shaped geometry to one O(1) and one O(10) atom. In the eighth Sn site, Sn(8) is bonded in a 3-coordinate geometry to one O(10), one O(11), and one O(16) atom. There are four 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. In the third P site, P(3) is bonded in a tetrahedral geometry to one O(11), one O(14), one O(15), and one O(18) atom. In the fourth P site, P(4) is bonded in a tetrahedral geometry to one O(12), one O(13), one O(16), and one O(17) atom. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(7), 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 120 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Sn(3) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(4), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Sn(5) and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Sn(1), one Sn(3), and one P(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Sn(1), one Sn(2), and one Sn(3) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Sn(6), one Sn(7), and one Sn(8) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Sn(8) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Sn(4) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Sn(5) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Sn(5) and one P(3) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Sn(6) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a bent 150 degrees geometry to one Sn(8) and one P(4) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Sn(6) and one P(4) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one P(3) atom.
MgSn8(P2O9)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), and one O(6) atom. The Mg(1)-O(1) bond length is 2.08 Å. The Mg(1)-O(2) bond length is 2.06 Å. The Mg(1)-O(5) bond length is 2.14 Å. The Mg(1)-O(6) bond length is 2.16 Å. There are eight inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted T-shaped geometry to one O(3), one O(8), and one O(9) atom. The Sn(1)-O(3) bond length is 2.21 Å. The Sn(1)-O(8) bond length is 2.25 Å. The Sn(1)-O(9) bond length is 2.13 Å. In the second Sn site, Sn(2) is bonded in an L-shaped geometry to one O(18) and one O(9) atom. The Sn(2)-O(18) bond length is 2.14 Å. The Sn(2)-O(9) bond length is 2.16 Å. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(8), and one O(9) atom. The Sn(3)-O(2) bond length is 2.28 Å. The Sn(3)-O(4) bond length is 2.19 Å. The Sn(3)-O(8) bond length is 2.68 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(12), one O(5), and one O(6) atom. The Sn(4)-O(12) bond length is 2.09 Å. The Sn(4)-O(5) bond length is 2.23 Å. The Sn(4)-O(6) bond length is 2.30 Å. In the fifth Sn site, Sn(5) is bonded in a distorted T-shaped geometry to one O(13), one O(14), and one O(7) atom. The Sn(5)-O(13) bond length is 2.17 Å. The Sn(5)-O(14) bond length is 2.14 Å. The Sn(5)-O(7) bond length is 2.18 Å. In the sixth Sn site, Sn(6) is bonded in a 3-coordinate geometry to one O(10), one O(15), and one O(17) atom. The Sn(6)-O(10) bond length is 2.12 Å. The Sn(6)-O(15) bond length is 2.17 Å. The Sn(6)-O(17) bond length is 2.14 Å. In the seventh Sn site, Sn(7) is bonded in an L-shaped geometry to one O(1) and one O(10) atom. The Sn(7)-O(1) bond length is 2.38 Å. The Sn(7)-O(10) bond length is 2.13 Å. In the eighth Sn site, Sn(8) is bonded in a 3-coordinate geometry to one O(10), one O(11), and one O(16) atom. The Sn(8)-O(10) bond length is 2.15 Å. The Sn(8)-O(11) bond length is 2.16 Å. The Sn(8)-O(16) bond length is 2.11 Å. There are four 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 1.59 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.59 Å. The P(1)-O(7) bond length is 1.52 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 1.51 Å. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(8) bond length is 1.56 Å. In the third P site, P(3) is bonded in a tetrahedral geometry to one O(11), one O(14), one O(15), and one O(18) atom. The P(3)-O(11) bond length is 1.57 Å. The P(3)-O(14) bond length is 1.55 Å. The P(3)-O(15) bond length is 1.55 Å. The P(3)-O(18) bond length is 1.55 Å. In the fourth P site, P(4) is bonded in a tetrahedral geometry to one O(12), one O(13), one O(16), and one O(17) atom. The P(4)-O(12) bond length is 1.56 Å. The P(4)-O(13) bond length is 1.56 Å. The P(4)-O(16) bond length is 1.55 Å. The P(4)-O(17) bond length is 1.54 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(7), 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 120 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Sn(3) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Sn(4), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Sn(5) and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Sn(1), one Sn(3), and one P(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Sn(1), one Sn(2), and one Sn(3) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Sn(6), one Sn(7), and one Sn(8) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Sn(8) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Sn(4) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Sn(5) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Sn(5) and one P(3) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Sn(6) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a bent 150 degrees geometry to one Sn(8) and one P(4) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Sn(6) and one P(4) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 150 degrees geometry to one Sn(2) and one P(3) atom.