LiMnP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(7) atoms to form distorted MnO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. 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 three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 29-47°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), 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 corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 48-56°. There are seven 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 3-coordinate 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 trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) 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 bent 150 degrees geometry to one Li(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one P(2) atom.
LiMnP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. The Li(1)-O(1) bond length is 2.03 Å. The Li(1)-O(2) bond length is 2.37 Å. The Li(1)-O(3) bond length is 2.13 Å. The Li(1)-O(5) bond length is 2.09 Å. The Li(1)-O(6) bond length is 1.90 Å. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(7) atoms to form distorted MnO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. The Mn(1)-O(1) bond length is 2.17 Å. The Mn(1)-O(2) bond length is 1.96 Å. The Mn(1)-O(3) bond length is 1.98 Å. The Mn(1)-O(5) bond length is 1.97 Å. There is one shorter (1.96 Å) and one longer (2.57 Å) Mn(1)-O(7) bond length. 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 three equivalent Mn(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 29-47°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.60 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), 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 corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 48-56°. The P(2)-O(4) bond length is 1.62 Å. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.48 Å. The P(2)-O(7) bond length is 1.57 Å. There are seven 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 3-coordinate 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 trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) 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 bent 150 degrees geometry to one Li(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one P(2) atom.