Li3Mn(BO3)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form LiO4 trigonal pyramids that share edges with two equivalent Mn(1)O5 square pyramids. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. In the third Li site, Li(3) is bonded in a distorted bent 120 degrees geometry to one O(3), one O(4), and one O(5) atom. Mn(1) is bonded to one O(1), one O(5), one O(6), and two equivalent O(2) atoms to form distorted MnO5 square pyramids that share  an edgeedge with one Mn(1)O5 square pyramid and edges with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(4), one O(5), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one B(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Mn(1), and one B(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), and one B(1) atom to form corner-sharing OLi3B tetrahedra. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one Li(3), and one B(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Mn(1), and one B(2) atom. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Mn(1), and one B(2) atom to form distorted corner-sharing OLi2MnB trigonal pyramids.
Li3Mn(BO3)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form LiO4 trigonal pyramids that share edges with two equivalent Mn(1)O5 square pyramids. The Li(1)-O(2) bond length is 2.20 Å. The Li(1)-O(3) bond length is 1.93 Å. The Li(1)-O(5) bond length is 2.00 Å. The Li(1)-O(6) bond length is 1.95 Å. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. The Li(2)-O(1) bond length is 2.37 Å. The Li(2)-O(3) bond length is 1.93 Å. The Li(2)-O(4) bond length is 1.96 Å. The Li(2)-O(6) bond length is 2.02 Å. In the third Li site, Li(3) is bonded in a distorted bent 120 degrees geometry to one O(3), one O(4), and one O(5) atom. The Li(3)-O(3) bond length is 1.96 Å. The Li(3)-O(4) bond length is 1.91 Å. The Li(3)-O(5) bond length is 2.46 Å. Mn(1) is bonded to one O(1), one O(5), one O(6), and two equivalent O(2) atoms to form distorted MnO5 square pyramids that share  an edgeedge with one Mn(1)O5 square pyramid and edges with two equivalent Li(1)O4 trigonal pyramids. The Mn(1)-O(1) bond length is 1.91 Å. The Mn(1)-O(5) bond length is 1.96 Å. The Mn(1)-O(6) bond length is 1.97 Å. There is one shorter (1.97 Å) and one longer (2.30 Å) Mn(1)-O(2) bond length. There are two inequivalent B sites. In the first B site, 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 1.38 Å. The B(1)-O(2) bond length is 1.41 Å. The B(1)-O(3) bond length is 1.36 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(4), one O(5), and one O(6) atom. The B(2)-O(4) bond length is 1.35 Å. The B(2)-O(5) bond length is 1.41 Å. The B(2)-O(6) bond length is 1.41 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one B(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Mn(1), and one B(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), and one B(1) atom to form corner-sharing OLi3B tetrahedra. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one Li(3), and one B(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Mn(1), and one B(2) atom. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Mn(1), and one B(2) atom to form distorted corner-sharing OLi2MnB trigonal pyramids.