Li3Mn3(PO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(1)O5 trigonal bipyramids. In the second Li site, Li(2) is bonded in a 2-coordinate geometry to one O(2) and one O(8) atom. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Li(1)O6 octahedra. In the second Mn site, Mn(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(7) atoms. 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(4) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with three equivalent Mn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-59°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra and corners with two equivalent Mn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Mn(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Li(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Mn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Mn(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Li(2) and one P(2) atom.
Li3Mn3(PO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(1)O5 trigonal bipyramids. Both Li(1)-O(3) bond lengths are 2.14 Å. Both Li(1)-O(4) bond lengths are 2.34 Å. Both Li(1)-O(5) bond lengths are 2.12 Å. In the second Li site, Li(2) is bonded in a 2-coordinate geometry to one O(2) and one O(8) atom. The Li(2)-O(2) bond length is 2.22 Å. The Li(2)-O(8) bond length is 1.91 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Li(1)O6 octahedra. The Mn(1)-O(1) bond length is 2.01 Å. The Mn(1)-O(2) bond length is 1.90 Å. The Mn(1)-O(4) bond length is 2.01 Å. The Mn(1)-O(5) bond length is 1.96 Å. The Mn(1)-O(7) bond length is 2.16 Å. In the second Mn site, Mn(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(7) atoms. Both Mn(2)-O(6) bond lengths are 1.92 Å. Both Mn(2)-O(7) bond lengths are 1.95 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(4) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with three equivalent Mn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 43-59°. The P(1)-O(1) bond length is 1.59 Å. The P(1)-O(2) bond length is 1.59 Å. The P(1)-O(3) bond length is 1.50 Å. The P(1)-O(4) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O6 octahedra and corners with two equivalent Mn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.57 Å. The P(2)-O(7) bond length is 1.62 Å. The P(2)-O(8) bond length is 1.49 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Mn(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Li(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Mn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Mn(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Li(2) and one P(2) atom.