Materials Data on Mn3As2 by Materials Project

Abstract

Mn3As2 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are six inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six As3- atoms to form MnAs6 octahedra that share corners with eight MnAs5 square pyramids, corners with five equivalent MnAs4 tetrahedra, corners with five MnAs5 trigonal bipyramids, edges with two equivalent MnAs6 octahedra, an edgeedge with one MnAs4 tetrahedra, edges with five MnAs5 trigonal bipyramids, and faces with two MnAs5 square pyramids. There are a spread of Mn–As bond distances ranging from 2.48–2.59 Å. In the second Mn2+ site, Mn2+ is bonded to five As3- atoms to form distorted MnAs5 trigonal bipyramids that share corners with three equivalent MnAs6 octahedra, corners with seven MnAs5 square pyramids, a cornercorner with one MnAs4 tetrahedra, corners with three MnAs5 trigonal bipyramids, edges with two equivalent MnAs6 octahedra, edges with three MnAs5 square pyramids, edges with two equivalent MnAs4 tetrahedra, and edges with two equivalent MnAs5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 28–45°. There are a spread of Mn–As bond distances ranging from 2.52–2.67 Å. In the third Mn2+ site, Mn2+ is bonded to five As3- atoms to form MnAs5 square pyramids that share corners with four equivalent MnAs6 octahedra, corners with three equivalent MnAs4 tetrahedra, corners with six MnAs5 trigonal bipyramids, edges with four MnAs5 square pyramids, an edgeedge with one MnAs4 tetrahedra, edges with three MnAs5 trigonal bipyramids, and a faceface with one MnAs6 octahedra. The corner-sharing octahedra tilt angles range from 54–55°. There are a spread of Mn–As bond distances ranging from 2.42–2.46 Å. In the fourth Mn2+ site, Mn2+ is bonded to five As3- atoms to form distorted MnAs5 trigonal bipyramids that share corners with two equivalent MnAs6 octahedra, corners with eight MnAs5 square pyramids, a cornercorner with one MnAs5 trigonal bipyramid, edges with three equivalent MnAs6 octahedra, edges with two MnAs5 square pyramids, edges with two equivalent MnAs4 tetrahedra, and edges with four MnAs5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. There are a spread of Mn–As bond distances ranging from 2.48–2.56 Å. In the fifth Mn2+ site, Mn2+ is bonded to five As3- atoms to form distorted MnAs5 square pyramids that share corners with four equivalent MnAs6 octahedra, corners with nine MnAs5 trigonal bipyramids, edges with four MnAs5 square pyramids, edges with two equivalent MnAs4 tetrahedra, edges with two MnAs5 trigonal bipyramids, and a faceface with one MnAs6 octahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Mn–As bond distances ranging from 2.38–2.55 Å. In the sixth Mn2+ site, Mn2+ is bonded to four As3- atoms to form distorted MnAs4 tetrahedra that share corners with five equivalent MnAs6 octahedra, corners with three equivalent MnAs5 square pyramids, corners with two equivalent MnAs4 tetrahedra, a cornercorner with one MnAs5 trigonal bipyramid, an edgeedge with one MnAs6 octahedra, edges with three MnAs5 square pyramids, and edges with four MnAs5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 18–50°. There are a spread of Mn–As bond distances ranging from 2.39–2.47 Å. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to eight Mn2+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to eight Mn2+ atoms. In the third As3- site, As3- is bonded to seven Mn2+ atoms to form distorted edge-sharing AsMn7 pentagonal bipyramids. In the fourth As3- site, As3- is bonded in a 7-coordinate geometry to seven Mn2+ atoms.