Zr3N4 crystallizes in the trigonal R-3m space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to three equivalent N(1) and four equivalent N(2) atoms. In the second Zr site, Zr(2) is bonded to six equivalent N(1) atoms to form edge-sharing ZrN6 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Zr(1) and three equivalent Zr(2) atoms to form NZr6 octahedra that share corners with three equivalent N(1)Zr6 octahedra, corners with six equivalent N(2)Zr4 tetrahedra, edges with nine equivalent N(1)Zr6 octahedra, and edges with three equivalent N(2)Zr4 tetrahedra. The corner-sharing octahedra are not tilted. In the second N site, N(2) is bonded to four equivalent Zr(1) atoms to form NZr4 tetrahedra that share corners with six equivalent N(1)Zr6 octahedra, corners with six equivalent N(2)Zr4 tetrahedra, edges with three equivalent N(1)Zr6 octahedra, and edges with three equivalent N(2)Zr4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-50°.
Zr3N4 crystallizes in the trigonal R-3m space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to three equivalent N(1) and four equivalent N(2) atoms. All Zr(1)-N(1) bond lengths are 2.60 Å. There are three shorter (2.05 Å) and one longer (2.28 Å) Zr(1)-N(2) bond length. In the second Zr site, Zr(2) is bonded to six equivalent N(1) atoms to form edge-sharing ZrN6 octahedra. All Zr(2)-N(1) bond lengths are 2.29 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Zr(1) and three equivalent Zr(2) atoms to form NZr6 octahedra that share corners with three equivalent N(1)Zr6 octahedra, corners with six equivalent N(2)Zr4 tetrahedra, edges with nine equivalent N(1)Zr6 octahedra, and edges with three equivalent N(2)Zr4 tetrahedra. The corner-sharing octahedra are not tilted. In the second N site, N(2) is bonded to four equivalent Zr(1) atoms to form NZr4 tetrahedra that share corners with six equivalent N(1)Zr6 octahedra, corners with six equivalent N(2)Zr4 tetrahedra, edges with three equivalent N(1)Zr6 octahedra, and edges with three equivalent N(2)Zr4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-50°.