Li2NiCuO4 is Caswellsilverite-derived structured and crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, edges with four equivalent Ni(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second Li site, Li(2) is bonded to two O(2,2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Ni(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. Ni(1) is bonded to two O(2,2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. Cu(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Li(2), two equivalent Ni(1), and one Cu(1) atom to form OLi3CuNi2 octahedra that share corners with six equivalent O(1)Li3CuNi2 octahedra; edges with four equivalent O(1)Li3CuNi2 octahedra; and edges with eight O(2,2)Li3Cu2Ni octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ni(1), and two equivalent Cu(1) atoms to form OLi3Cu2Ni octahedra that share corners with six O(2,2)Li3Cu2Ni octahedra; edges with four equivalent O(2)Li3Cu2Ni octahedra; and edges with eight equivalent O(1)Li3CuNi2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ni(1), and two equivalent Cu(1) atoms to form OLi3Cu2Ni octahedra that share corners with six O(2,2)Li3Cu2Ni octahedra; edges with four equivalent O(2)Li3Cu2Ni octahedra; and edges with eight equivalent O(1)Li3CuNi2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°.
Li2NiCuO4 is Caswellsilverite-derived structured and crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, edges with four equivalent Ni(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. Both Li(1)-O(1) bond lengths are 2.29 Å. All Li(1)-O(2) bond lengths are 2.05 Å. In the second Li site, Li(2) is bonded to two O(2,2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Ni(1)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. Both Li(2)-O(2,2) bond lengths are 2.21 Å. All Li(2)-O(1) bond lengths are 2.06 Å. Ni(1) is bonded to two O(2,2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. Both Ni(1)-O(2,2) bond lengths are 1.97 Å. All Ni(1)-O(1) bond lengths are 2.06 Å. Cu(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CuO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, edges with four equivalent Li(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. Both Cu(1)-O(1) bond lengths are 1.89 Å. All Cu(1)-O(2) bond lengths are 2.05 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Li(2), two equivalent Ni(1), and one Cu(1) atom to form OLi3CuNi2 octahedra that share corners with six equivalent O(1)Li3CuNi2 octahedra; edges with four equivalent O(1)Li3CuNi2 octahedra; and edges with eight O(2,2)Li3Cu2Ni octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ni(1), and two equivalent Cu(1) atoms to form OLi3Cu2Ni octahedra that share corners with six O(2,2)Li3Cu2Ni octahedra; edges with four equivalent O(2)Li3Cu2Ni octahedra; and edges with eight equivalent O(1)Li3CuNi2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(2) is bonded to one Li(2), two equivalent Li(1), one Ni(1), and two equivalent Cu(1) atoms to form OLi3Cu2Ni octahedra that share corners with six O(2,2)Li3Cu2Ni octahedra; edges with four equivalent O(2)Li3Cu2Ni octahedra; and edges with eight equivalent O(1)Li3CuNi2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. Both O(2)-Li(1) bond lengths are 2.05 Å. Both O(2)-Cu(1) bond lengths are 2.05 Å.