V4NiCuO12 crystallizes in the monoclinic C2 space group. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(3), and one O(7) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(3)O4 tetrahedra, and  a cornercorner with one V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-60°. In the second V site, V(2) is bonded to one O(2), one O(4), one O(8), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(3)O4 tetrahedra, and  a cornercorner with one V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-60°. 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 Cu(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, and  a cornercorner with one V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-63°. 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 Cu(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, and  a cornercorner with one V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-63°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(12), two equivalent O(2), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent V(2)O4 tetrahedra, corners with four equivalent V(4)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(11), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with two equivalent V(1)O4 tetrahedra, corners with four equivalent V(3)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. Cu(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 distorted CuO6 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,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)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 Ni(2), and one Cu(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one Cu(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one Cu(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(2) and one Cu(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one V(3), one Ni(2), and one Cu(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one V(4), one Ni(1), and one Cu(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(2) and one V(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one V(1) 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(2) 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.
V4NiCuO12 crystallizes in the monoclinic C2 space group. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(3), and one O(7) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(3)O4 tetrahedra, and  a cornercorner with one V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-60°. The V(1)-O(1) bond length is 1.74 Å. The V(1)-O(10) bond length is 1.79 Å. The V(1)-O(3) bond length is 1.69 Å. The V(1)-O(7) bond length is 1.78 Å. In the second V site, V(2) is bonded to one O(2), one O(4), one O(8), and one O(9) atom to form VO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra,  a cornercorner with one V(3)O4 tetrahedra, and  a cornercorner with one V(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-60°. The V(2)-O(2) bond length is 1.74 Å. The V(2)-O(4) bond length is 1.69 Å. The V(2)-O(8) bond length is 1.78 Å. The V(2)-O(9) bond length is 1.79 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 Cu(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, and  a cornercorner with one V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-63°. The V(3)-O(11) bond length is 1.68 Å. The V(3)-O(5) bond length is 1.69 Å. The V(3)-O(7) bond length is 1.81 Å. The V(3)-O(9) bond length is 1.82 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 Cu(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, and  a cornercorner with one V(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-63°. The V(4)-O(10) bond length is 1.81 Å. The V(4)-O(12) bond length is 1.68 Å. The V(4)-O(6) bond length is 1.69 Å. The V(4)-O(8) bond length is 1.81 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(12), two equivalent O(2), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent V(2)O4 tetrahedra, corners with four equivalent V(4)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. Both Ni(1)-O(12) bond lengths are 2.00 Å. Both Ni(1)-O(2) bond lengths are 2.24 Å. Both Ni(1)-O(6) bond lengths are 2.04 Å. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(11), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with two equivalent V(1)O4 tetrahedra, corners with four equivalent V(3)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. Both Ni(2)-O(1) bond lengths are 2.23 Å. Both Ni(2)-O(11) bond lengths are 2.01 Å. Both Ni(2)-O(5) bond lengths are 2.04 Å. Cu(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 distorted CuO6 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,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The Cu(1)-O(1) bond length is 2.02 Å. The Cu(1)-O(2) bond length is 2.02 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(4) bond length is 1.97 Å. The Cu(1)-O(5) bond length is 2.40 Å. The Cu(1)-O(6) bond length is 2.41 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 Ni(2), and one Cu(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one Cu(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one Cu(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one V(2) and one Cu(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one V(3), one Ni(2), and one Cu(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one V(4), one Ni(1), and one Cu(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(2) and one V(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one V(1) 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(2) 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.