Materials Data on NaZn4As3 by Materials Project

NaZn4As3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Na1+ is bonded to six equivalent As3- atoms to form NaAs6 octahedra that share corners with twelve ZnAs4 tetrahedra, edges with six equivalent NaAs6 octahedra, and edges with six equivalent ZnAs4 tetrahedra. All Na–As bond lengths are 3.10 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four As3- atoms to form distorted ZnAs4 tetrahedra that share corners with three equivalent NaAs6 octahedra, corners with ten ZnAs4 tetrahedra, edges with three equivalent NaAs6 octahedra, and edges with three equivalent ZnAs4 tetrahedra. The corner-sharing octahedral tilt angles are 26°. There are three shorter (2.48 Å) and one longer (3.02 Å) Zn–As bond lengths. In the second Zn2+ site, Zn2+ is bonded to four As3- atoms to form ZnAs4 tetrahedra that share corners with three equivalent NaAs6 octahedra, corners with twelve ZnAs4 tetrahedra, and edges with six ZnAs4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are one shorter (2.48 Å) and three longer (2.65 Å) Zn–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 7-coordinate geometry to three equivalent Na1+ and four Zn2+ atoms. In the second As3- site, As3- is bonded in a distorted body-centered cubic geometry to eight Zn2+ atoms.