LiMnP2O7 crystallizes in the triclinic P-1 space group. Li(1) is bonded to one O(2), one O(6), one O(7), and two equivalent O(4) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and  an edgeedge with one Li(1)O5 trigonal bipyramid. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form distorted MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three 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(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and corners with three equivalent Mn(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Mn(1)O5 trigonal bipyramids, and corners with four equivalent Li(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to 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(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Li(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom.
LiMnP2O7 crystallizes in the triclinic P-1 space group. Li(1) is bonded to one O(2), one O(6), one O(7), and two equivalent O(4) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and  an edgeedge with one Li(1)O5 trigonal bipyramid. The Li(1)-O(2) bond length is 2.27 Å. The Li(1)-O(6) bond length is 2.19 Å. The Li(1)-O(7) bond length is 2.23 Å. There is one shorter (2.06 Å) and one longer (2.16 Å) Li(1)-O(4) bond length. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form distorted MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and corners with three equivalent Li(1)O5 trigonal bipyramids. The Mn(1)-O(1) bond length is 2.06 Å. The Mn(1)-O(2) bond length is 1.93 Å. The Mn(1)-O(3) bond length is 1.93 Å. The Mn(1)-O(6) bond length is 2.02 Å. The Mn(1)-O(7) bond length is 1.93 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and corners with three equivalent Mn(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.50 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.62 Å. The P(1)-O(7) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Mn(1)O5 trigonal bipyramids, and corners with four equivalent Li(1)O5 trigonal bipyramids. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.61 Å. The P(2)-O(6) bond length is 1.56 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to 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(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Li(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Mn(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one P(1) atom.