Materials Data on Mg2CuSi3 by Materials Project

Abstract

Mg2CuSi3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg is bonded in a 12-coordinate geometry to four equivalent Mg, three equivalent Cu, and nine equivalent Si atoms. There are one shorter (2.95 Å) and three longer (3.21 Å) Mg–Mg bond lengths. All Mg–Cu bond lengths are 3.11 Å. There are three shorter (2.84 Å) and six longer (3.05 Å) Mg–Si bond lengths. Cu is bonded to six equivalent Mg and six equivalent Si atoms to form CuMg6Si6 cuboctahedra that share corners with six equivalent CuMg6Si6 cuboctahedra, corners with twelve equivalent SiMg6Cu2Si4 cuboctahedra, edges with six equivalent CuMg6Si6 cuboctahedra, and faces with eighteen equivalent SiMg6Cu2Si4 cuboctahedra. All Cu–Si bond lengths are 2.47 Å. Si is bonded to six equivalent Mg, two equivalent Cu, and four equivalent Si atoms to form SiMg6Cu2Si4 cuboctahedra that share corners with four equivalent CuMg6Si6 cuboctahedra, corners with fourteen equivalent SiMg6Cu2Si4 cuboctahedra, edges with six equivalent SiMg6Cu2Si4 cuboctahedra, faces with six equivalent CuMg6Si6 cuboctahedra, and faces with twelve equivalent SiMg6Cu2Si4 cuboctahedra. All Si–Si bond lengths are 2.67 Å.