ZnSnP2O7 crystallizes in the triclinic P-1 space group. Zn(1) is bonded to one O(1), one O(3), one O(7), and two equivalent O(4) atoms to form distorted ZnO5 square pyramids that share  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Zn(1)O5 square pyramid, and  an edgeedge with one Sn(1)O5 square pyramid. Sn(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form distorted SnO5 square pyramids that share  a cornercorner with one Zn(1)O5 square pyramid, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Zn(1)O5 square pyramid. 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 PO4 tetrahedra that share corners with two equivalent Zn(1)O5 square pyramids, corners with three equivalent Sn(1)O5 square pyramids, and  a cornercorner with one P(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids, corners with three equivalent Zn(1)O5 square pyramids, and  a cornercorner with one P(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Zn(1), one Sn(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Zn(1), one Sn(1), and one P(2) atom.
ZnSnP2O7 crystallizes in the triclinic P-1 space group. Zn(1) is bonded to one O(1), one O(3), one O(7), and two equivalent O(4) atoms to form distorted ZnO5 square pyramids that share  a cornercorner with one Sn(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Zn(1)O5 square pyramid, and  an edgeedge with one Sn(1)O5 square pyramid. The Zn(1)-O(1) bond length is 2.01 Å. The Zn(1)-O(3) bond length is 2.01 Å. The Zn(1)-O(7) bond length is 2.36 Å. There is one shorter (2.07 Å) and one longer (2.21 Å) Zn(1)-O(4) bond length. Sn(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form distorted SnO5 square pyramids that share  a cornercorner with one Zn(1)O5 square pyramid, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Zn(1)O5 square pyramid. The Sn(1)-O(1) bond length is 2.66 Å. The Sn(1)-O(2) bond length is 2.18 Å. The Sn(1)-O(3) bond length is 2.56 Å. The Sn(1)-O(5) bond length is 2.14 Å. The Sn(1)-O(7) bond length is 2.58 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 PO4 tetrahedra that share corners with two equivalent Zn(1)O5 square pyramids, corners with three equivalent Sn(1)O5 square pyramids, and  a cornercorner with one P(2)O4 tetrahedra. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(6) bond length is 1.63 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids, corners with three equivalent Zn(1)O5 square pyramids, and  a cornercorner with one P(1)O4 tetrahedra. The P(2)-O(4) bond length is 1.57 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.63 Å. The P(2)-O(7) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Zn(1), one Sn(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Zn(1), one Sn(1), and one P(2) atom.