MgLa4WNi3O12 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(5) atoms. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 2-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the second La site, La(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. W(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form WO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra and corners with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent Ni(3)O6 octahedra and corners with four equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. In the second Ni site, Ni(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with two equivalent W(1)O6 octahedra and corners with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third Ni site, Ni(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1), two equivalent La(2), one Ni(1), and one Ni(3) atom to form distorted OLa4Ni2 octahedra that share corners with six equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(3)La2MgNi2 trigonal bipyramids, corners with two equivalent O(5)La2MgNi2 trigonal bipyramids, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with four equivalent O(2)La4NiW octahedra, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and edges with two equivalent O(4)La2NiW trigonal pyramids. The corner-sharing octahedral tilt angles range from 0-20°. In the second O site, O(2) is bonded to two equivalent La(1), two equivalent La(2), one W(1), and one Ni(2) atom to form distorted OLa4NiW octahedra that share corners with six equivalent O(2)La4NiW octahedra, corners with two equivalent O(3)La2MgNi2 trigonal bipyramids, corners with two equivalent O(5)La2MgNi2 trigonal bipyramids, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with four equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and edges with two equivalent O(4)La2NiW trigonal pyramids. The corner-sharing octahedral tilt angles range from 0-22°. In the third O site, O(3) is bonded to one Mg(1), two equivalent La(2), one Ni(2), and one Ni(3) atom to form distorted OLa2MgNi2 trigonal bipyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with three equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra,  an edgeedge with one O(3)La2MgNi2 trigonal bipyramid, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and faces with two equivalent O(5)La2MgNi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 51-52°. In the fourth O site, O(4) is bonded to two equivalent La(1), one W(1), and one Ni(1) atom to form distorted OLa2NiW trigonal pyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra, and  an edgeedge with one O(4)La2NiW trigonal pyramid. The corner-sharing octahedral tilt angles range from 54-57°. In the fifth O site, O(5) is bonded to one Mg(1), two equivalent La(2), one Ni(2), and one Ni(3) atom to form distorted OLa2MgNi2 trigonal bipyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with three equivalent O(5)La2MgNi2 trigonal bipyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra,  an edgeedge with one O(5)La2MgNi2 trigonal bipyramid, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, and faces with two equivalent O(3)La2MgNi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 51-53°. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to two equivalent La(2), one W(1), and one Ni(1) atom.
MgLa4WNi3O12 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(5) atoms. Both Mg(1)-O(3) bond lengths are 1.99 Å. Both Mg(1)-O(5) bond lengths are 2.00 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 2-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Both La(1)-O(1) bond lengths are 2.78 Å. Both La(1)-O(2) bond lengths are 2.83 Å. Both La(1)-O(4) bond lengths are 2.24 Å. In the second La site, La(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. Both La(2)-O(1) bond lengths are 2.84 Å. Both La(2)-O(2) bond lengths are 2.79 Å. Both La(2)-O(3) bond lengths are 2.69 Å. Both La(2)-O(5) bond lengths are 2.65 Å. Both La(2)-O(6) bond lengths are 3.07 Å. W(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form WO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra and corners with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. Both W(1)-O(2) bond lengths are 2.11 Å. Both W(1)-O(4) bond lengths are 2.07 Å. Both W(1)-O(6) bond lengths are 2.00 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent Ni(3)O6 octahedra and corners with four equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-31°. Both Ni(1)-O(1) bond lengths are 2.21 Å. Both Ni(1)-O(4) bond lengths are 1.98 Å. Both Ni(1)-O(6) bond lengths are 2.02 Å. In the second Ni site, Ni(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with two equivalent W(1)O6 octahedra and corners with four equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. Both Ni(2)-O(2) bond lengths are 2.38 Å. Both Ni(2)-O(3) bond lengths are 1.94 Å. Both Ni(2)-O(5) bond lengths are 1.96 Å. In the third Ni site, Ni(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. Both Ni(3)-O(1) bond lengths are 2.28 Å. Both Ni(3)-O(3) bond lengths are 1.96 Å. Both Ni(3)-O(5) bond lengths are 1.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1), two equivalent La(2), one Ni(1), and one Ni(3) atom to form distorted OLa4Ni2 octahedra that share corners with six equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(3)La2MgNi2 trigonal bipyramids, corners with two equivalent O(5)La2MgNi2 trigonal bipyramids, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with four equivalent O(2)La4NiW octahedra, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and edges with two equivalent O(4)La2NiW trigonal pyramids. The corner-sharing octahedral tilt angles range from 0-20°. In the second O site, O(2) is bonded to two equivalent La(1), two equivalent La(2), one W(1), and one Ni(2) atom to form distorted OLa4NiW octahedra that share corners with six equivalent O(2)La4NiW octahedra, corners with two equivalent O(3)La2MgNi2 trigonal bipyramids, corners with two equivalent O(5)La2MgNi2 trigonal bipyramids, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with four equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and edges with two equivalent O(4)La2NiW trigonal pyramids. The corner-sharing octahedral tilt angles range from 0-22°. In the third O site, O(3) is bonded to one Mg(1), two equivalent La(2), one Ni(2), and one Ni(3) atom to form distorted OLa2MgNi2 trigonal bipyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with three equivalent O(3)La2MgNi2 trigonal bipyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra,  an edgeedge with one O(3)La2MgNi2 trigonal bipyramid, edges with two equivalent O(5)La2MgNi2 trigonal bipyramids, and faces with two equivalent O(5)La2MgNi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 51-52°. In the fourth O site, O(4) is bonded to two equivalent La(1), one W(1), and one Ni(1) atom to form distorted OLa2NiW trigonal pyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with two equivalent O(4)La2NiW trigonal pyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra, and  an edgeedge with one O(4)La2NiW trigonal pyramid. The corner-sharing octahedral tilt angles range from 54-57°. In the fifth O site, O(5) is bonded to one Mg(1), two equivalent La(2), one Ni(2), and one Ni(3) atom to form distorted OLa2MgNi2 trigonal bipyramids that share corners with two equivalent O(1)La4Ni2 octahedra, corners with two equivalent O(2)La4NiW octahedra, corners with three equivalent O(5)La2MgNi2 trigonal bipyramids, edges with two equivalent O(1)La4Ni2 octahedra, edges with two equivalent O(2)La4NiW octahedra,  an edgeedge with one O(5)La2MgNi2 trigonal bipyramid, edges with two equivalent O(3)La2MgNi2 trigonal bipyramids, and faces with two equivalent O(3)La2MgNi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 51-53°. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to two equivalent La(2), one W(1), and one Ni(1) atom.