Materials Data on CuNi3O4 by Materials Project
Ni3CuO4 is Caswellsilverite-like structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent NiO6 octahedra, edges with four equivalent CuO6 octahedra, and edges with eight NiO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are four shorter (2.11 Å) and two longer (2.12 Å) Ni–O bond lengths. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent CuO6 octahedra, edges with two equivalent CuO6 octahedra, and edges with ten NiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.08 Å) and four longer (2.09 Å) Ni–O bond lengths. Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with six equivalent NiO6 octahedra, edges with two equivalent CuO6 octahedra, and edges with ten NiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are four shorter (2.13 Å) and two longer (2.17 Å) Cu–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five Ni2+ and one Cu2+ atom to form a mixture of corner and edge-sharing OCuNi5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to four Ni2+ and two equivalent Cu2+ atoms to form OCu2Ni4 octahedra that share corners with six equivalent OCu2Ni4 octahedra and edges with twelve OCuNi5 octahedra. The corner-sharing octahedral tilt angles are 0°.