Mn3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O5 square pyramids, corners with six equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(2)O5 square pyramids. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted MnO5 square pyramids that share  a cornercorner with one Mn(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O5 square pyramid, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O5 square pyramids, and  an edgeedge with one Mn(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 32-52°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one P(1) atom.
Mn3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O5 square pyramids, corners with six equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(2)O5 square pyramids. Both Mn(1)-O(2) bond lengths are 2.22 Å. Both Mn(1)-O(3) bond lengths are 2.24 Å. Both Mn(1)-O(4) bond lengths are 2.13 Å. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted MnO5 square pyramids that share  a cornercorner with one Mn(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O5 square pyramid, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. The Mn(2)-O(2) bond length is 2.13 Å. The Mn(2)-O(3) bond length is 2.05 Å. The Mn(2)-O(4) bond length is 2.28 Å. There is one shorter (2.05 Å) and one longer (2.11 Å) Mn(2)-O(1) bond length. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O5 square pyramids, and  an edgeedge with one Mn(2)O5 square pyramid. The corner-sharing octahedral tilt angles range from 32-52°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.53 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one P(1) atom.