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 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(6) atom. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MnO6 octahedra that share 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(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-49°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the second O site, O(2) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Li(2), one Mn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one Mn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the sixth O site, O(6) 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(7) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) 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 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. The Li(1)-O(1) bond length is 2.04 Å. The Li(1)-O(2) bond length is 1.97 Å. The Li(1)-O(4) bond length is 2.47 Å. The Li(1)-O(5) bond length is 2.00 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(6) atom. The Li(2)-O(1) bond length is 2.10 Å. The Li(2)-O(2) bond length is 2.19 Å. The Li(2)-O(3) bond length is 2.54 Å. The Li(2)-O(5) bond length is 2.23 Å. The Li(2)-O(6) bond length is 2.10 Å. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MnO6 octahedra that share 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 2.45 Å. The Mn(1)-O(2) bond length is 2.26 Å. The Mn(1)-O(3) bond length is 2.14 Å. The Mn(1)-O(4) bond length is 2.08 Å. The Mn(1)-O(5) bond length is 2.25 Å. The Mn(1)-O(6) bond length is 2.12 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.51 Å. The P(1)-O(6) bond length is 1.54 Å. The P(1)-O(7) bond length is 1.65 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-49°. The P(2)-O(1) bond length is 1.55 Å. The P(2)-O(2) bond length is 1.55 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.62 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the second O site, O(2) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Li(2), one Mn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one Mn(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one P(2) atom. In the sixth O site, O(6) 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(7) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom.