La2Mn3Sb3O14 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms to form LaO8 hexagonal bipyramids that share edges with two equivalent La(2)O8 hexagonal bipyramids, edges with four equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. In the second La site, La(2) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms to form LaO8 hexagonal bipyramids that share edges with two equivalent La(1)O8 hexagonal bipyramids, edges with four equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent La(2)O8 hexagonal bipyramids, and edges with four equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-48°. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted MnO8 hexagonal bipyramids that share edges with two equivalent La(1)O8 hexagonal bipyramids, edges with two equivalent La(2)O8 hexagonal bipyramids, edges with two equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Sb(2)O6 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent La(1)O8 hexagonal bipyramids, and edges with four equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-47°. In the second Sb site, Sb(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent La(1)O8 hexagonal bipyramids, edges with two equivalent La(2)O8 hexagonal bipyramids, and edges with two equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-48°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one La(1), one La(2), and two equivalent Mn(2) atoms to form OLa2Mn2 tetrahedra that share corners with two equivalent O(3)La2Sb2 tetrahedra, corners with four equivalent O(1)La2Mn2 tetrahedra, corners with four equivalent O(4)LaMn2Sb tetrahedra, corners with four equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra, edges with two equivalent O(4)LaMn2Sb tetrahedra, and edges with two equivalent O(5)LaMnSb2 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mn(1), two equivalent Mn(2), and one Sb(1) atom. In the third O site, O(3) is bonded to one La(1), one La(2), and two equivalent Sb(2) atoms to form distorted OLa2Sb2 tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with four equivalent O(3)La2Sb2 tetrahedra, corners with four equivalent O(4)LaMn2Sb tetrahedra, corners with four equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra, edges with two equivalent O(4)LaMn2Sb tetrahedra, and edges with two equivalent O(5)LaMnSb2 tetrahedra. In the fourth O site, O(4) is bonded to one La(2), one Mn(1), one Mn(2), and one Sb(2) atom to form distorted OLaMn2Sb tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with two equivalent O(3)La2Sb2 tetrahedra, corners with two equivalent O(5)LaMnSb2 tetrahedra, corners with six equivalent O(4)LaMn2Sb tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra,  an edgeedge with one O(4)LaMn2Sb tetrahedra, and  an edgeedge with one O(5)LaMnSb2 tetrahedra. In the fifth O site, O(5) is bonded to one La(1), one Mn(2), one Sb(1), and one Sb(2) atom to form distorted OLaMnSb2 tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with two equivalent O(3)La2Sb2 tetrahedra, corners with two equivalent O(4)LaMn2Sb tetrahedra, corners with six equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra,  an edgeedge with one O(4)LaMn2Sb tetrahedra, and  an edgeedge with one O(5)LaMnSb2 tetrahedra.
La2Mn3Sb3O14 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms to form LaO8 hexagonal bipyramids that share edges with two equivalent La(2)O8 hexagonal bipyramids, edges with four equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. Both La(1)-O(1) bond lengths are 2.35 Å. Both La(1)-O(3) bond lengths are 2.56 Å. All La(1)-O(5) bond lengths are 2.60 Å. In the second La site, La(2) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms to form LaO8 hexagonal bipyramids that share edges with two equivalent La(1)O8 hexagonal bipyramids, edges with four equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. Both La(2)-O(1) bond lengths are 2.39 Å. Both La(2)-O(3) bond lengths are 2.61 Å. All La(2)-O(4) bond lengths are 2.57 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent La(2)O8 hexagonal bipyramids, and edges with four equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-48°. Both Mn(1)-O(2) bond lengths are 1.97 Å. All Mn(1)-O(4) bond lengths are 2.10 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted MnO8 hexagonal bipyramids that share edges with two equivalent La(1)O8 hexagonal bipyramids, edges with two equivalent La(2)O8 hexagonal bipyramids, edges with two equivalent Mn(2)O8 hexagonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Sb(2)O6 octahedra. Both Mn(2)-O(1) bond lengths are 2.18 Å. Both Mn(2)-O(2) bond lengths are 2.65 Å. Both Mn(2)-O(4) bond lengths are 2.59 Å. Both Mn(2)-O(5) bond lengths are 2.58 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(2) and four equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent La(1)O8 hexagonal bipyramids, and edges with four equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-47°. Both Sb(1)-O(2) bond lengths are 2.00 Å. All Sb(1)-O(5) bond lengths are 2.02 Å. In the second Sb site, Sb(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent La(1)O8 hexagonal bipyramids, edges with two equivalent La(2)O8 hexagonal bipyramids, and edges with two equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-48°. Both Sb(2)-O(3) bond lengths are 2.03 Å. Both Sb(2)-O(4) bond lengths are 1.96 Å. Both Sb(2)-O(5) bond lengths are 2.03 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one La(1), one La(2), and two equivalent Mn(2) atoms to form OLa2Mn2 tetrahedra that share corners with two equivalent O(3)La2Sb2 tetrahedra, corners with four equivalent O(1)La2Mn2 tetrahedra, corners with four equivalent O(4)LaMn2Sb tetrahedra, corners with four equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra, edges with two equivalent O(4)LaMn2Sb tetrahedra, and edges with two equivalent O(5)LaMnSb2 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mn(1), two equivalent Mn(2), and one Sb(1) atom. In the third O site, O(3) is bonded to one La(1), one La(2), and two equivalent Sb(2) atoms to form distorted OLa2Sb2 tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with four equivalent O(3)La2Sb2 tetrahedra, corners with four equivalent O(4)LaMn2Sb tetrahedra, corners with four equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra, edges with two equivalent O(4)LaMn2Sb tetrahedra, and edges with two equivalent O(5)LaMnSb2 tetrahedra. In the fourth O site, O(4) is bonded to one La(2), one Mn(1), one Mn(2), and one Sb(2) atom to form distorted OLaMn2Sb tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with two equivalent O(3)La2Sb2 tetrahedra, corners with two equivalent O(5)LaMnSb2 tetrahedra, corners with six equivalent O(4)LaMn2Sb tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra,  an edgeedge with one O(4)LaMn2Sb tetrahedra, and  an edgeedge with one O(5)LaMnSb2 tetrahedra. In the fifth O site, O(5) is bonded to one La(1), one Mn(2), one Sb(1), and one Sb(2) atom to form distorted OLaMnSb2 tetrahedra that share corners with two equivalent O(1)La2Mn2 tetrahedra, corners with two equivalent O(3)La2Sb2 tetrahedra, corners with two equivalent O(4)LaMn2Sb tetrahedra, corners with six equivalent O(5)LaMnSb2 tetrahedra,  an edgeedge with one O(1)La2Mn2 tetrahedra,  an edgeedge with one O(3)La2Sb2 tetrahedra,  an edgeedge with one O(4)LaMn2Sb tetrahedra, and  an edgeedge with one O(5)LaMnSb2 tetrahedra.