Li2MnP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal planar geometry to one O(3), one O(6), and one O(7) atom. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form distorted LiO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, 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 61-72°. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form MnO6 octahedra that share corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-54°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-52°. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Mn(1), and one P(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one P(2) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one P(1), and one P(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Mn(1), and one P(1) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom.
Li2MnP2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal planar geometry to one O(3), one O(6), and one O(7) atom. The Li(1)-O(3) bond length is 1.92 Å. The Li(1)-O(6) bond length is 1.91 Å. The Li(1)-O(7) bond length is 1.92 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form distorted LiO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, 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 61-72°. The Li(2)-O(1) bond length is 1.94 Å. The Li(2)-O(2) bond length is 2.10 Å. The Li(2)-O(4) bond length is 2.24 Å. The Li(2)-O(5) bond length is 1.97 Å. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form MnO6 octahedra that share corners with three equivalent Li(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. The Mn(1)-O(1) bond length is 2.29 Å. The Mn(1)-O(2) bond length is 2.15 Å. The Mn(1)-O(3) bond length is 2.31 Å. The Mn(1)-O(5) bond length is 2.18 Å. The Mn(1)-O(6) bond length is 2.19 Å. The Mn(1)-O(7) bond length is 2.25 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-54°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.65 Å. The P(1)-O(5) bond length is 1.53 Å. The P(1)-O(6) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-52°. The P(2)-O(2) bond length is 1.53 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(4) bond length is 1.65 Å. The P(2)-O(7) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Mn(1), and one P(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one P(2) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one P(1), and one P(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Mn(1), and one P(1) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom.