Li2Mn(BO3)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent Mn(1)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 29-67°. 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 Li(1)O5 trigonal bipyramids and edges with two equivalent Li(1)O5 trigonal bipyramids. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Mn(1), and one B(1) atom to form a mixture of distorted corner and edge-sharing OLi2MnB trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Mn(1), and one B(1) atom to form a mixture of distorted corner and edge-sharing OLi2MnB tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Mn(1), and one B(1) atom.
Li2Mn(BO3)2 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent Mn(1)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 29-67°. The Li(1)-O(3) bond length is 2.02 Å. There is one shorter (2.15 Å) and one longer (2.23 Å) Li(1)-O(1) bond length. Both Li(1)-O(2) bond lengths are 2.18 Å. 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 Li(1)O5 trigonal bipyramids and edges with two equivalent Li(1)O5 trigonal bipyramids. Both Mn(1)-O(1) bond lengths are 1.95 Å. Both Mn(1)-O(2) bond lengths are 1.94 Å. Both Mn(1)-O(3) bond lengths are 1.95 Å. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The B(1)-O(1) bond length is 1.39 Å. The B(1)-O(2) bond length is 1.38 Å. The B(1)-O(3) bond length is 1.39 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Mn(1), and one B(1) atom to form a mixture of distorted corner and edge-sharing OLi2MnB trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Mn(1), and one B(1) atom to form a mixture of distorted corner and edge-sharing OLi2MnB tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Mn(1), and one B(1) atom.