Mn4(PO4)3 crystallizes in the tetragonal I-42d space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are two inequivalent P sites. In the first P site, P(1) is bonded to four equivalent O(3) atoms to form PO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra and corners with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  an edgeedge with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-48°. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(2) atom. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom.
Mn4(PO4)3 crystallizes in the tetragonal I-42d space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Mn(1)-O(1) bond lengths are 2.27 Å. Both Mn(1)-O(2) bond lengths are 2.15 Å. Both Mn(1)-O(3) bond lengths are 2.22 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. Both Mn(2)-O(1) bond lengths are 2.21 Å. Both Mn(2)-O(2) bond lengths are 2.11 Å. Both Mn(2)-O(3) bond lengths are 2.11 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to four equivalent O(3) atoms to form PO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra and corners with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. All P(1)-O(3) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  an edgeedge with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-48°. Both P(2)-O(1) bond lengths are 1.55 Å. Both P(2)-O(2) bond lengths are 1.58 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(2) atom. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom.