Materials Data on MgTi2 by Materials Project

Abstract

MgTi2 is beta-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to four Mg and eight Ti atoms to form MgMg4Ti8 cuboctahedra that share corners with six equivalent TiMg4Ti8 cuboctahedra, corners with twelve MgMg4Ti8 cuboctahedra, edges with three equivalent MgMg4Ti8 cuboctahedra, edges with fifteen TiMg4Ti8 cuboctahedra, faces with six MgMg4Ti8 cuboctahedra, and faces with fourteen TiMg2Ti10 cuboctahedra. There are two shorter (2.88 Å) and two longer (2.98 Å) Mg–Mg bond lengths. There are a spread of Mg–Ti bond distances ranging from 2.90–3.03 Å. In the second Mg site, Mg is bonded to four Mg and eight Ti atoms to form MgMg4Ti8 cuboctahedra that share corners with six equivalent TiMg4Ti8 cuboctahedra, corners with twelve MgMg4Ti8 cuboctahedra, edges with three equivalent MgMg4Ti8 cuboctahedra, edges with fifteen TiMg2Ti10 cuboctahedra, faces with six MgMg4Ti8 cuboctahedra, and faces with fourteen TiMg2Ti10 cuboctahedra. Both Mg–Mg bond lengths are 2.88 Å. There are a spread of Mg–Ti bond distances ranging from 2.99–3.04 Å. There are four inequivalent Ti sites. In the first Ti site, Ti is bonded to two equivalent Mg and ten Ti atoms to form TiMg2Ti10 cuboctahedra that share corners with eighteen TiMg2Ti10 cuboctahedra, edges with eight equivalent MgMg4Ti8 cuboctahedra, edges with ten TiMg4Ti8 cuboctahedra, faces with eight MgMg4Ti8 cuboctahedra, and faces with twelve TiMg2Ti10 cuboctahedra. There are a spread of Ti–Ti bond distances ranging from 2.87–2.98 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 eighteen TiMg2Ti10 cuboctahedra, edges with six TiMg2Ti10 cuboctahedra, edges with twelve MgMg4Ti8 cuboctahedra, faces with six MgMg4Ti8 cuboctahedra, and faces with fourteen TiMg2Ti10 cuboctahedra. There are a spread of Ti–Ti bond distances ranging from 2.88–3.03 Å. In the third Ti site, Ti is bonded to six Mg and six Ti atoms to form TiMg6Ti6 cuboctahedra that share corners with eighteen TiMg2Ti10 cuboctahedra, edges with four equivalent MgMg4Ti8 cuboctahedra, edges with fourteen TiMg2Ti10 cuboctahedra, faces with ten MgMg4Ti8 cuboctahedra, and faces with ten TiMg2Ti10 cuboctahedra. Both Ti–Ti bond lengths are 2.88 Å. In the fourth Ti site, Ti is bonded to four Mg and eight Ti atoms to form distorted TiMg4Ti8 cuboctahedra that share corners with six equivalent TiMg4Ti8 cuboctahedra, corners with twelve MgMg4Ti8 cuboctahedra, edges with six MgMg4Ti8 cuboctahedra, edges with twelve TiMg2Ti10 cuboctahedra, faces with four MgMg4Ti8 cuboctahedra, and faces with sixteen TiMg2Ti10 cuboctahedra. Both Ti–Ti bond lengths are 2.88 Å.