MnSn(PO4)2 crystallizes in the monoclinic P2_1/m space group. Mn(1) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted MnO6 octahedra that share corners with four equivalent Sn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-52°. Sn(1) is bonded to one O(2), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form SnO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(5) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra, corners with three equivalent Mn(1)O6 octahedra, and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the second P site, P(2) is bonded to one O(3), one O(4), and two equivalent O(6) atoms to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with three equivalent Sn(1)O6 octahedra, and  an edgeedge with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to 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 Mn(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sn(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sn(1), and one P(2) atom.
MnSn(PO4)2 crystallizes in the monoclinic P2_1/m space group. Mn(1) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted MnO6 octahedra that share corners with four equivalent Sn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-52°. The Mn(1)-O(1) bond length is 2.08 Å. The Mn(1)-O(3) bond length is 2.10 Å. Both Mn(1)-O(5) bond lengths are 2.20 Å. Both Mn(1)-O(6) bond lengths are 2.36 Å. Sn(1) is bonded to one O(2), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form SnO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-52°. The Sn(1)-O(2) bond length is 2.03 Å. The Sn(1)-O(4) bond length is 2.04 Å. Both Sn(1)-O(5) bond lengths are 2.16 Å. Both Sn(1)-O(6) bond lengths are 2.12 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(5) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra, corners with three equivalent Mn(1)O6 octahedra, and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-59°. The P(1)-O(1) bond length is 1.50 Å. The P(1)-O(2) bond length is 1.55 Å. Both P(1)-O(5) bond lengths are 1.59 Å. In the second P site, P(2) is bonded to one O(3), one O(4), and two equivalent O(6) atoms to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with three equivalent Sn(1)O6 octahedra, and  an edgeedge with one Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. The P(2)-O(3) bond length is 1.50 Å. The P(2)-O(4) bond length is 1.56 Å. Both P(2)-O(6) bond lengths are 1.59 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to 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 Mn(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sn(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sn(1), and one P(2) atom.