Materials Data on MnNiSe2 by Materials Project
MnNiSe2 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mn2+ is bonded to six equivalent Se2- atoms to form MnSe6 octahedra that share corners with twelve equivalent NiSe6 octahedra, edges with six equivalent MnSe6 octahedra, and faces with two equivalent NiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are four shorter (2.47 Å) and two longer (2.48 Å) Mn–Se bond lengths. Ni2+ is bonded to six equivalent Se2- atoms to form NiSe6 octahedra that share corners with twelve equivalent MnSe6 octahedra, edges with six equivalent NiSe6 octahedra, and faces with two equivalent MnSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Ni–Se bond distances ranging from 2.49–2.54 Å. Se2- is bonded in a 6-coordinate geometry to three equivalent Mn2+ and three equivalent Ni2+ atoms.