Materials Data on CaSi2 by Materials Project

Abstract

CaSi2 is hexagonal omega structure structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Ca is bonded to six equivalent Si atoms to form distorted CaSi6 octahedra that share corners with six equivalent SiCa3Si3 octahedra, edges with six equivalent CaSi6 octahedra, and edges with six equivalent SiCa3Si3 octahedra. The corner-sharing octahedral tilt angles are 21°. All Ca–Si bond lengths are 3.04 Å. Si is bonded to three equivalent Ca and three equivalent Si atoms to form distorted SiCa3Si3 octahedra that share corners with three equivalent CaSi6 octahedra, corners with three equivalent SiCa3Si3 octahedra, edges with three equivalent CaSi6 octahedra, and edges with nine equivalent SiCa3Si3 octahedra. The corner-sharing octahedra tilt angles range from 0–21°. All Si–Si bond lengths are 2.40 Å.