Li3MnB4O9 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), two equivalent O(4), and two equivalent O(6) atoms. Mn(1) is bonded to one O(3), one O(5), and two equivalent O(6) atoms to form MnO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and  a cornercorner with one B(2)O4 tetrahedra. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form BO4 tetrahedra that share  a cornercorner with one Mn(1)O4 tetrahedra and  a cornercorner with one B(2)O4 tetrahedra. In the second B site, B(2) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form BO4 tetrahedra that share  a cornercorner with one Mn(1)O4 tetrahedra and  a cornercorner with one B(1)O4 tetrahedra. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one B(1), and one B(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to two equivalent Li(1), one Mn(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one B(2), and one B(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one B(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one B(3) atom.
Li3MnB4O9 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. The Li(1)-O(1) bond length is 2.10 Å. The Li(1)-O(3) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.49 Å. The Li(1)-O(6) bond length is 1.97 Å. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), two equivalent O(4), and two equivalent O(6) atoms. The Li(2)-O(2) bond length is 1.97 Å. The Li(2)-O(5) bond length is 2.39 Å. Both Li(2)-O(4) bond lengths are 2.13 Å. Both Li(2)-O(6) bond lengths are 2.39 Å. Mn(1) is bonded to one O(3), one O(5), and two equivalent O(6) atoms to form MnO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and  a cornercorner with one B(2)O4 tetrahedra. The Mn(1)-O(3) bond length is 1.89 Å. The Mn(1)-O(5) bond length is 1.84 Å. Both Mn(1)-O(6) bond lengths are 1.98 Å. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form BO4 tetrahedra that share  a cornercorner with one Mn(1)O4 tetrahedra and  a cornercorner with one B(2)O4 tetrahedra. The B(1)-O(2) bond length is 1.46 Å. The B(1)-O(5) bond length is 1.45 Å. Both B(1)-O(1) bond lengths are 1.52 Å. In the second B site, B(2) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form BO4 tetrahedra that share  a cornercorner with one Mn(1)O4 tetrahedra and  a cornercorner with one B(1)O4 tetrahedra. The B(2)-O(2) bond length is 1.45 Å. The B(2)-O(3) bond length is 1.46 Å. Both B(2)-O(4) bond lengths are 1.51 Å. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. The B(3)-O(1) bond length is 1.40 Å. The B(3)-O(4) bond length is 1.38 Å. The B(3)-O(6) bond length is 1.38 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one B(1), and one B(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to two equivalent Li(1), one Mn(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one B(2), and one B(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Mn(1), and one B(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Mn(1), and one B(3) atom.