MgSnP2O7 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. Sn(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(6) 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(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Mg(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Mg(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Sn(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Sn(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(2) atom.
MgSnP2O7 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The Mg(1)-O(2) bond length is 2.25 Å. The Mg(1)-O(3) bond length is 1.99 Å. The Mg(1)-O(4) bond length is 2.07 Å. There is one shorter (2.05 Å) and one longer (2.35 Å) Mg(1)-O(5) bond length. Sn(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(6) atoms. The Sn(1)-O(2) bond length is 2.60 Å. The Sn(1)-O(4) bond length is 2.49 Å. The Sn(1)-O(7) bond length is 2.20 Å. There is one shorter (2.40 Å) and one longer (2.41 Å) Sn(1)-O(6) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Mg(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.62 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Mg(1)O5 trigonal bipyramids. The P(2)-O(1) bond length is 1.66 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(4) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Sn(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Sn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Sn(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(2) atom.