Materials Data on Mg2MnAs2 by Materials Project

Abstract

Mg2MnAs2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six As3- atoms to form MgAs6 octahedra that share corners with six equivalent MgAs4 tetrahedra, corners with six equivalent MnAs4 tetrahedra, edges with six equivalent MgAs6 octahedra, edges with three equivalent MgAs4 tetrahedra, and edges with three equivalent MnAs4 tetrahedra. There are three shorter (2.90 Å) and three longer (2.91 Å) Mg–As bond lengths. In the second Mg2+ site, Mg2+ is bonded to four As3- atoms to form MgAs4 tetrahedra that share corners with six equivalent MgAs6 octahedra, corners with six equivalent MgAs4 tetrahedra, edges with three equivalent MgAs6 octahedra, and edges with three equivalent MnAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–57°. There are three shorter (2.60 Å) and one longer (2.70 Å) Mg–As bond lengths. Mn2+ is bonded to four As3- atoms to form MnAs4 tetrahedra that share corners with six equivalent MgAs6 octahedra, corners with six equivalent MnAs4 tetrahedra, edges with three equivalent MgAs6 octahedra, and edges with three equivalent MgAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–57°. There are three shorter (2.59 Å) and one longer (2.70 Å) Mn–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to four Mg2+ and three equivalent Mn2+ atoms to form distorted AsMg4Mn3 pentagonal bipyramids that share corners with three equivalent AsMg6Mn pentagonal bipyramids and edges with twelve AsMg4Mn3 pentagonal bipyramids. In the second As3- site, As3- is bonded to six Mg2+ and one Mn2+ atom to form a mixture of distorted edge and corner-sharing AsMg6Mn pentagonal bipyramids.