Materials Data on BaLi2(MgSi)2 by Materials Project

Abstract

Li2Ba(MgSi)2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Li1+ is bonded in a trigonal planar geometry to three equivalent Si4- atoms. All Li–Si bond lengths are 2.65 Å. Ba2+ is bonded to six equivalent Si4- atoms to form BaSi6 octahedra that share corners with eighteen equivalent MgSi4 tetrahedra, edges with six equivalent BaSi6 octahedra, and faces with two equivalent MgSi4 tetrahedra. All Ba–Si bond lengths are 3.56 Å. Mg2+ is bonded to four equivalent Si4- atoms to form MgSi4 tetrahedra that share corners with nine equivalent BaSi6 octahedra, corners with six equivalent MgSi4 tetrahedra, edges with three equivalent MgSi4 tetrahedra, and a faceface with one BaSi6 octahedra. The corner-sharing octahedra tilt angles range from 48–52°. There are one shorter (2.78 Å) and three longer (2.89 Å) Mg–Si bond lengths. Si4- is bonded in a 10-coordinate geometry to three equivalent Li1+, three equivalent Ba2+, and four equivalent Mg2+ atoms.