Materials Data on Mn3CrAs4 by Materials Project
CrMn3As4 is Modderite-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Cr6+ is bonded to six As3- atoms to form distorted CrAs6 octahedra that share corners with twelve MnAs6 octahedra, edges with two equivalent CrAs6 octahedra, edges with four equivalent MnAs6 octahedra, and faces with two equivalent MnAs6 octahedra. The corner-sharing octahedra tilt angles range from 44–58°. There are a spread of Cr–As bond distances ranging from 2.37–2.58 Å. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six As3- atoms to form distorted MnAs6 octahedra that share corners with four equivalent CrAs6 octahedra, corners with eight equivalent MnAs6 octahedra, edges with six MnAs6 octahedra, and faces with two equivalent CrAs6 octahedra. The corner-sharing octahedra tilt angles range from 44–58°. There are a spread of Mn–As bond distances ranging from 2.38–2.60 Å. In the second Mn2+ site, Mn2+ is bonded to six As3- atoms to form distorted MnAs6 octahedra that share corners with twelve MnAs6 octahedra, edges with two equivalent MnAs6 octahedra, edges with four equivalent CrAs6 octahedra, and faces with two equivalent MnAs6 octahedra. The corner-sharing octahedra tilt angles range from 44–58°. There are a spread of Mn–As bond distances ranging from 2.36–2.58 Å. In the third Mn2+ site, Mn2+ is bonded to six As3- atoms to form distorted MnAs6 octahedra that share corners with four equivalent MnAs6 octahedra, corners with eight equivalent CrAs6 octahedra, edges with six MnAs6 octahedra, and faces with two equivalent MnAs6 octahedra. The corner-sharing octahedra tilt angles range from 44–58°. There are a spread of Mn–As bond distances ranging from 2.37–2.57 Å. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded in a 6-coordinate geometry to one Cr6+ and five Mn2+ atoms. In the second As3- site, As3- is bonded in a 6-coordinate geometry to one Cr6+ and five Mn2+ atoms. In the third As3- site, As3- is bonded in a 6-coordinate geometry to two equivalent Cr6+ and four Mn2+ atoms. In the fourth As3- site, As3- is bonded in a 6-coordinate geometry to two equivalent Cr6+ and four Mn2+ atoms.