V4FeNiO12 crystallizes in the triclinic P1 space group. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(3), one O(7), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent V(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-58°. In the second V site, V(2) is bonded to one O(10), one O(2), one O(4), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-58°. In the third V site, V(3) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and corners with two equivalent V(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-60°. In the fourth V site, V(4) is bonded to one O(10), one O(12), one O(6), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and corners with two equivalent V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-60°. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share  a cornercorner with one V(3)O4 tetrahedra,  a cornercorner with one V(4)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. Ni(1) is bonded to one O(1), one O(11), one O(12), one O(2), one O(5), and one O(6) atom to form NiO6 octahedra that share  a cornercorner with one V(1)O4 tetrahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(3)O4 tetrahedra, corners with two equivalent V(4)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar 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 trigonal planar geometry to one V(2), one Fe(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one Fe(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(2) and one Fe(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one V(3), one Fe(1), and one Ni(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one V(4), one Fe(1), and one Ni(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one V(1) and one V(3) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one V(2) and one V(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one V(1) and one V(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one V(2) and one V(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one V(3) and one Ni(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one V(4) and one Ni(1) atom.
V4FeNiO12 crystallizes in the triclinic P1 space group. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(3), one O(7), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent V(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-58°. The V(1)-O(1) bond length is 1.72 Å. The V(1)-O(3) bond length is 1.68 Å. The V(1)-O(7) bond length is 1.80 Å. The V(1)-O(9) bond length is 1.80 Å. In the second V site, V(2) is bonded to one O(10), one O(2), one O(4), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-58°. The V(2)-O(10) bond length is 1.79 Å. The V(2)-O(2) bond length is 1.72 Å. The V(2)-O(4) bond length is 1.68 Å. The V(2)-O(8) bond length is 1.80 Å. In the third V site, V(3) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and corners with two equivalent V(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-60°. The V(3)-O(11) bond length is 1.68 Å. The V(3)-O(5) bond length is 1.72 Å. The V(3)-O(7) bond length is 1.80 Å. The V(3)-O(9) bond length is 1.80 Å. In the fourth V site, V(4) is bonded to one O(10), one O(12), one O(6), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and corners with two equivalent V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-60°. The V(4)-O(10) bond length is 1.80 Å. The V(4)-O(12) bond length is 1.68 Å. The V(4)-O(6) bond length is 1.72 Å. The V(4)-O(8) bond length is 1.80 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share  a cornercorner with one V(3)O4 tetrahedra,  a cornercorner with one V(4)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.16 Å. The Fe(1)-O(2) bond length is 2.15 Å. The Fe(1)-O(3) bond length is 2.09 Å. The Fe(1)-O(4) bond length is 2.08 Å. The Fe(1)-O(5) bond length is 2.23 Å. The Fe(1)-O(6) bond length is 2.22 Å. Ni(1) is bonded to one O(1), one O(11), one O(12), one O(2), one O(5), and one O(6) atom to form NiO6 octahedra that share  a cornercorner with one V(1)O4 tetrahedra,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(3)O4 tetrahedra, corners with two equivalent V(4)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. The Ni(1)-O(1) bond length is 2.13 Å. The Ni(1)-O(11) bond length is 2.05 Å. The Ni(1)-O(12) bond length is 2.06 Å. The Ni(1)-O(2) bond length is 2.14 Å. The Ni(1)-O(5) bond length is 2.13 Å. The Ni(1)-O(6) bond length is 2.14 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar 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 trigonal planar geometry to one V(2), one Fe(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one Fe(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(2) and one Fe(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one V(3), one Fe(1), and one Ni(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one V(4), one Fe(1), and one Ni(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one V(1) and one V(3) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one V(2) and one V(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one V(1) and one V(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one V(2) and one V(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one V(3) and one Ni(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one V(4) and one Ni(1) atom.