Materials Data on NaMnCuSe2 by Materials Project

NaCuMnSe2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with six equivalent MnSe4 tetrahedra, corners with six equivalent CuSe4 tetrahedra, edges with six equivalent NaSe6 octahedra, edges with three equivalent MnSe4 tetrahedra, and edges with three equivalent CuSe4 tetrahedra. There are three shorter (3.00 Å) and three longer (3.08 Å) Na–Se bond lengths. Mn2+ is bonded to four Se2- atoms to form MnSe4 tetrahedra that share corners with six equivalent NaSe6 octahedra, corners with six equivalent MnSe4 tetrahedra, edges with three equivalent NaSe6 octahedra, and edges with three equivalent CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–53°. There are one shorter (2.47 Å) and three longer (2.58 Å) Mn–Se bond lengths. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with six equivalent NaSe6 octahedra, corners with six equivalent CuSe4 tetrahedra, edges with three equivalent NaSe6 octahedra, and edges with three equivalent MnSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–51°. There are three shorter (2.51 Å) and one longer (2.65 Å) Cu–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Na1+, three equivalent Mn2+, and one Cu1+ atom to form distorted SeNa3Mn3Cu pentagonal bipyramids that share corners with three equivalent SeNa3MnCu3 pentagonal bipyramids and edges with twelve SeNa3Mn3Cu pentagonal bipyramids. In the second Se2- site, Se2- is bonded to three equivalent Na1+, one Mn2+, and three equivalent Cu1+ atoms to form a mixture of distorted edge and corner-sharing SeNa3MnCu3 pentagonal bipyramids.