Materials Data on MgTi2 by Materials Project

Abstract

MgTi2 is beta-derived structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Mg is bonded to two equivalent Mg and ten Ti atoms to form MgMg2Ti10 cuboctahedra that share corners with six equivalent MgMg2Ti10 cuboctahedra, corners with twelve TiMg6Ti6 cuboctahedra, edges with eight equivalent MgMg2Ti10 cuboctahedra, edges with ten TiMg6Ti6 cuboctahedra, faces with six equivalent MgMg2Ti10 cuboctahedra, and faces with fourteen TiMg6Ti6 cuboctahedra. Both Mg–Mg bond lengths are 2.95 Å. There are a spread of Mg–Ti bond distances ranging from 2.96–3.02 Å. There are two inequivalent Ti sites. In the first Ti site, Ti is bonded to six equivalent Mg and six Ti atoms to form distorted TiMg6Ti6 cuboctahedra that share corners with six equivalent MgMg2Ti10 cuboctahedra, corners with twelve TiMg6Ti6 cuboctahedra, edges with seven equivalent MgMg2Ti10 cuboctahedra, edges with eleven equivalent TiMg4Ti8 cuboctahedra, faces with six equivalent MgMg2Ti10 cuboctahedra, and faces with fourteen TiMg6Ti6 cuboctahedra. There are a spread of Ti–Ti bond distances ranging from 2.86–3.10 Å. In the second Ti site, Ti is bonded to four equivalent Mg and eight Ti atoms to form TiMg4Ti8 cuboctahedra that share corners with six equivalent MgMg2Ti10 cuboctahedra, corners with twelve TiMg6Ti6 cuboctahedra, edges with three equivalent MgMg2Ti10 cuboctahedra, edges with fifteen TiMg6Ti6 cuboctahedra, faces with eight equivalent MgMg2Ti10 cuboctahedra, and faces with twelve TiMg6Ti6 cuboctahedra. There are two shorter (2.95 Å) and four longer (3.00 Å) Ti–Ti bond lengths.