Materials Data on CaMg2N2 by Materials Project
CaMg2N2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Ca2+ is bonded to six equivalent N3- atoms to form CaN6 octahedra that share corners with twelve equivalent MgN4 tetrahedra, edges with six equivalent CaN6 octahedra, and edges with six equivalent MgN4 tetrahedra. All Ca–N bond lengths are 2.62 Å. Mg2+ is bonded to four equivalent N3- atoms to form MgN4 tetrahedra that share corners with six equivalent CaN6 octahedra, corners with six equivalent MgN4 tetrahedra, edges with three equivalent CaN6 octahedra, and edges with three equivalent MgN4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–52°. There are three shorter (2.13 Å) and one longer (2.29 Å) Mg–N bond lengths. N3- is bonded in a 7-coordinate geometry to three equivalent Ca2+ and four equivalent Mg2+ atoms.