TiNiCu2O4 crystallizes in the trigonal R-3m space group. Ti(1) is bonded to six equivalent O(2) atoms to form edge-sharing TiO6 octahedra. Ni(1) is bonded to six equivalent O(1) atoms to form edge-sharing NiO6 octahedra. Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ni(1) and one Cu(1) atom to form distorted OCuNi3 trigonal pyramids that share  a cornercorner with one O(2)Ti3Cu trigonal pyramid, corners with nine equivalent O(1)CuNi3 trigonal pyramids, and edges with three equivalent O(1)CuNi3 trigonal pyramids. In the second O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid, corners with nine equivalent O(2)Ti3Cu trigonal pyramids, and edges with three equivalent O(2)Ti3Cu trigonal pyramids. In the third O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid; corners with nine O(2,2)Ti3Cu trigonal pyramids; and edges with three equivalent O(2)Ti3Cu trigonal pyramids. In the fourth O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid; corners with nine O(2,2)Ti3Cu trigonal pyramids; and edges with three equivalent O(2)Ti3Cu trigonal pyramids.
TiNiCu2O4 crystallizes in the trigonal R-3m space group. Ti(1) is bonded to six equivalent O(2) atoms to form edge-sharing TiO6 octahedra. All Ti(1)-O(2) bond lengths are 2.04 Å. Ni(1) is bonded to six equivalent O(1) atoms to form edge-sharing NiO6 octahedra. All Ni(1)-O(1) bond lengths are 2.03 Å. Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. The Cu(1)-O(1) bond length is 1.80 Å. The Cu(1)-O(2) bond length is 1.88 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ni(1) and one Cu(1) atom to form distorted OCuNi3 trigonal pyramids that share  a cornercorner with one O(2)Ti3Cu trigonal pyramid, corners with nine equivalent O(1)CuNi3 trigonal pyramids, and edges with three equivalent O(1)CuNi3 trigonal pyramids. In the second O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid, corners with nine equivalent O(2)Ti3Cu trigonal pyramids, and edges with three equivalent O(2)Ti3Cu trigonal pyramids. In the third O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid; corners with nine O(2,2)Ti3Cu trigonal pyramids; and edges with three equivalent O(2)Ti3Cu trigonal pyramids. All O(2)-Ti(1) bond lengths are 2.04 Å. The O(2)-Cu(1) bond length is 1.88 Å. In the fourth O site, O(2) is bonded to three equivalent Ti(1) and one Cu(1) atom to form distorted OTi3Cu trigonal pyramids that share  a cornercorner with one O(1)CuNi3 trigonal pyramid; corners with nine O(2,2)Ti3Cu trigonal pyramids; and edges with three equivalent O(2)Ti3Cu trigonal pyramids. All O(2)-Ti(1) bond lengths are 2.04 Å. The O(2)-Cu(1) bond length is 1.88 Å.