Materials Data on PrZnAgAs2 by Materials Project

Abstract

PrAgZnAs2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. Pr3+ is bonded to six As3- atoms to form PrAs6 octahedra that share corners with six equivalent AgAs4 tetrahedra, corners with six equivalent ZnAs4 tetrahedra, edges with six equivalent PrAs6 octahedra, edges with three equivalent AgAs4 tetrahedra, and edges with three equivalent ZnAs4 tetrahedra. There are three shorter (2.99 Å) and three longer (3.11 Å) Pr–As bond lengths. Ag1+ is bonded to four As3- atoms to form AgAs4 tetrahedra that share corners with six equivalent PrAs6 octahedra, corners with six equivalent AgAs4 tetrahedra, edges with three equivalent PrAs6 octahedra, and edges with three equivalent ZnAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–54°. There are three shorter (2.64 Å) and one longer (2.71 Å) Ag–As bond lengths. Zn2+ is bonded to four As3- atoms to form ZnAs4 tetrahedra that share corners with six equivalent PrAs6 octahedra, corners with six equivalent ZnAs4 tetrahedra, edges with three equivalent PrAs6 octahedra, and edges with three equivalent AgAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–57°. There are one shorter (2.64 Å) and three longer (2.66 Å) Zn–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to three equivalent Pr3+, one Ag1+, and three equivalent Zn2+ atoms to form distorted AsPr3Zn3Ag pentagonal bipyramids that share corners with three equivalent AsPr3ZnAg3 pentagonal bipyramids and edges with twelve AsPr3Zn3Ag pentagonal bipyramids. In the second As3- site, As3- is bonded to three equivalent Pr3+, three equivalent Ag1+, and one Zn2+ atom to form a mixture of distorted edge and corner-sharing AsPr3ZnAg3 pentagonal bipyramids.