Materials Data on Sr(MnAs)2 by Materials Project

Abstract

SrMn2As2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Sr2+ is bonded to six equivalent As3- atoms to form SrAs6 octahedra that share corners with twelve equivalent MnAs4 tetrahedra, edges with six equivalent SrAs6 octahedra, and edges with six equivalent MnAs4 tetrahedra. All Sr–As bond lengths are 3.14 Å. Mn2+ is bonded to four equivalent As3- atoms to form MnAs4 tetrahedra that share corners with six equivalent SrAs6 octahedra, corners with six equivalent MnAs4 tetrahedra, edges with three equivalent SrAs6 octahedra, and edges with three equivalent MnAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–49°. There are one shorter (2.43 Å) and three longer (2.48 Å) Mn–As bond lengths. As3- is bonded in a 7-coordinate geometry to three equivalent Sr2+ and four equivalent Mn2+ atoms.