SrSn(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Sn(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted SnO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Sn(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. 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(7) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Sr(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in an L-shaped geometry to one Sn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Sn(1), and one P(2) atom.
SrSn(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. The Sr(1)-O(2) bond length is 2.42 Å. The Sr(1)-O(3) bond length is 2.97 Å. The Sr(1)-O(4) bond length is 2.87 Å. The Sr(1)-O(8) bond length is 3.22 Å. There is one shorter (2.44 Å) and one longer (2.64 Å) Sr(1)-O(1) bond length. There is one shorter (2.61 Å) and one longer (2.78 Å) Sr(1)-O(6) bond length. Sn(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted SnO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Sn(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The Sn(1)-O(3) bond length is 2.04 Å. The Sn(1)-O(4) bond length is 2.16 Å. The Sn(1)-O(5) bond length is 2.09 Å. The Sn(1)-O(7) bond length is 1.98 Å. There is one shorter (2.15 Å) and one longer (2.43 Å) Sn(1)-O(8) 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(3), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-56°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.51 Å. The P(1)-O(3) bond length is 1.60 Å. The P(1)-O(7) bond length is 1.59 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. The P(2)-O(4) bond length is 1.59 Å. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(6) bond length is 1.51 Å. The P(2)-O(8) bond length is 1.63 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Sr(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in an L-shaped geometry to one Sn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Sn(1), and one P(2) atom.