Li2Mn(PO4)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form distorted LiO4 trigonal pyramids that share corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. 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 six equivalent P(1)O4 tetrahedra and edges with two equivalent Li(1)O4 trigonal pyramids. 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 and corners with four equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 42-46°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(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(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(1) atom.
Li2Mn(PO4)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form distorted LiO4 trigonal pyramids that share corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The Li(1)-O(1) bond length is 2.01 Å. The Li(1)-O(2) bond length is 2.18 Å. There is one shorter (1.92 Å) and one longer (2.01 Å) Li(1)-O(4) bond length. 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 six equivalent P(1)O4 tetrahedra and edges with two equivalent Li(1)O4 trigonal pyramids. Both Mn(1)-O(1) bond lengths are 1.94 Å. Both Mn(1)-O(2) bond lengths are 1.96 Å. Both Mn(1)-O(3) bond lengths are 1.90 Å. 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 and corners with four equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 42-46°. The P(1)-O(1) bond length is 1.56 Å. The P(1)-O(2) bond length is 1.58 Å. The P(1)-O(3) bond length is 1.57 Å. The P(1)-O(4) bond length is 1.51 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(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(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(1) atom.