Materials Data on MnCuAs by Materials Project
CuMnAs crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mn2+ is bonded to five equivalent As3- atoms to form distorted MnAs5 trigonal bipyramids that share corners with eight equivalent CuAs4 tetrahedra, corners with eight equivalent MnAs5 trigonal bipyramids, edges with six equivalent CuAs4 tetrahedra, and edges with six equivalent MnAs5 trigonal bipyramids. There are a spread of Mn–As bond distances ranging from 2.60–2.72 Å. Cu1+ is bonded to four equivalent As3- atoms to form distorted CuAs4 tetrahedra that share corners with eight equivalent CuAs4 tetrahedra, corners with eight equivalent MnAs5 trigonal bipyramids, edges with two equivalent CuAs4 tetrahedra, and edges with six equivalent MnAs5 trigonal bipyramids. There are a spread of Cu–As bond distances ranging from 2.41–2.50 Å. As3- is bonded in a 9-coordinate geometry to five equivalent Mn2+ and four equivalent Cu1+ atoms.