MgV4FeNiO12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(12), one O(2), one O(4), one O(6), and one O(9) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one V(1)O5 trigonal bipyramid,  a cornercorner with one V(3)O5 trigonal bipyramid,  an edgeedge with one V(1)O5 trigonal bipyramid, and  an edgeedge with one V(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 60°. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(2)O5 trigonal bipyramid,  a cornercorner with one V(3)O5 trigonal bipyramid,  an edgeedge with one Mg(1)O5 square pyramid, and  an edgeedge with one V(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 54°. In the second V site, V(2) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted VO5 trigonal bipyramids that share corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Mg(1)O5 square pyramid,  an edgeedge with one V(1)O5 trigonal bipyramid, and  an edgeedge with one V(3)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-49°. In the third V site, V(3) is bonded to one O(10), one O(5), one O(7), one O(8), and one O(9) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(7), one O(8), and one O(9) atom. Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(2), one O(3), and one O(5) atom. Ni(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(3), and one O(8) atom to form distorted NiO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(1)O5 trigonal bipyramid, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one V(3)O5 trigonal bipyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one V(1), one Fe(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one V(2), one Fe(1), and one Ni(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one V(1), one V(2), one V(3), and one Fe(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one V(3) and one V(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal pyramidal geometry to one V(2), one V(3), one V(4), and one Ni(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one V(3), and one V(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one V(3), one Fe(1), and one Ni(1) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one V(4) and one Ni(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(4), and one Ni(1) atom.
MgV4FeNiO12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(12), one O(2), one O(4), one O(6), and one O(9) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one V(1)O5 trigonal bipyramid,  a cornercorner with one V(3)O5 trigonal bipyramid,  an edgeedge with one V(1)O5 trigonal bipyramid, and  an edgeedge with one V(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 60°. The Mg(1)-O(12) bond length is 2.17 Å. The Mg(1)-O(2) bond length is 2.07 Å. The Mg(1)-O(4) bond length is 2.10 Å. The Mg(1)-O(6) bond length is 2.01 Å. The Mg(1)-O(9) bond length is 2.17 Å. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(2)O5 trigonal bipyramid,  a cornercorner with one V(3)O5 trigonal bipyramid,  an edgeedge with one Mg(1)O5 square pyramid, and  an edgeedge with one V(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 54°. The V(1)-O(1) bond length is 1.78 Å. The V(1)-O(2) bond length is 1.93 Å. The V(1)-O(4) bond length is 1.87 Å. The V(1)-O(5) bond length is 2.13 Å. The V(1)-O(6) bond length is 1.90 Å. In the second V site, V(2) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted VO5 trigonal bipyramids that share corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Mg(1)O5 square pyramid,  an edgeedge with one V(1)O5 trigonal bipyramid, and  an edgeedge with one V(3)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-49°. The V(2)-O(3) bond length is 1.84 Å. The V(2)-O(4) bond length is 1.86 Å. The V(2)-O(5) bond length is 2.13 Å. The V(2)-O(6) bond length is 1.92 Å. The V(2)-O(8) bond length is 1.79 Å. In the third V site, V(3) is bonded to one O(10), one O(5), one O(7), one O(8), and one O(9) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. The V(3)-O(10) bond length is 1.79 Å. The V(3)-O(5) bond length is 1.86 Å. The V(3)-O(7) bond length is 1.82 Å. The V(3)-O(8) bond length is 2.29 Å. The V(3)-O(9) bond length is 1.91 Å. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(7), one O(8), and one O(9) atom. The V(4)-O(11) bond length is 1.67 Å. The V(4)-O(12) bond length is 1.77 Å. The V(4)-O(7) bond length is 1.82 Å. The V(4)-O(8) bond length is 2.31 Å. The V(4)-O(9) bond length is 1.89 Å. Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(2), one O(3), and one O(5) atom. The Fe(1)-O(1) bond length is 2.06 Å. The Fe(1)-O(10) bond length is 1.90 Å. The Fe(1)-O(2) bond length is 1.88 Å. The Fe(1)-O(3) bond length is 1.98 Å. The Fe(1)-O(5) bond length is 2.19 Å. Ni(1) is bonded to one O(1), one O(10), one O(11), one O(12), one O(3), and one O(8) atom to form distorted NiO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one V(1)O5 trigonal bipyramid, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one V(3)O5 trigonal bipyramid. The Ni(1)-O(1) bond length is 2.14 Å. The Ni(1)-O(10) bond length is 2.20 Å. The Ni(1)-O(11) bond length is 2.01 Å. The Ni(1)-O(12) bond length is 2.09 Å. The Ni(1)-O(3) bond length is 2.02 Å. The Ni(1)-O(8) bond length is 2.06 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one V(1), one Fe(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one V(2), one Fe(1), and one Ni(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one V(1), one V(2), one V(3), and one Fe(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one V(3) and one V(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal pyramidal geometry to one V(2), one V(3), one V(4), and one Ni(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Mg(1), one V(3), and one V(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one V(3), one Fe(1), and one Ni(1) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one V(4) and one Ni(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(4), and one Ni(1) atom.