Materials Data on Mg2Ti by Materials Project

Abstract

Mg2Ti is beta-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded to nine Mg and three Ti atoms to form MgMg9Ti3 cuboctahedra that share corners with eighteen MgMg9Ti3 cuboctahedra, edges with eight MgMg7Ti5 cuboctahedra, edges with ten TiMg8Ti4 cuboctahedra, faces with seven TiMg8Ti4 cuboctahedra, and faces with thirteen MgMg9Ti3 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.96–3.15 Å. There are two shorter (3.15 Å) and one longer (3.24 Å) Mg–Ti bond lengths. In the second Mg site, Mg is bonded to seven Mg and five Ti atoms to form MgMg7Ti5 cuboctahedra that share corners with eighteen MgMg9Ti3 cuboctahedra, edges with eight TiMg8Ti4 cuboctahedra, edges with ten MgMg9Ti3 cuboctahedra, faces with eight TiMg8Ti4 cuboctahedra, and faces with twelve MgMg9Ti3 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.96–3.10 Å. There are a spread of Mg–Ti bond distances ranging from 3.03–3.19 Å. In the third Mg site, Mg is bonded to eight Mg and four Ti atoms to form distorted MgMg8Ti4 cuboctahedra that share corners with eighteen MgMg9Ti3 cuboctahedra, edges with six TiMg8Ti4 cuboctahedra, edges with twelve MgMg9Ti3 cuboctahedra, faces with nine TiMg8Ti4 cuboctahedra, and faces with eleven MgMg9Ti3 cuboctahedra. There are two shorter (2.96 Å) and two longer (3.14 Å) Mg–Mg bond lengths. There are a spread of Mg–Ti bond distances ranging from 2.96–3.24 Å. In the fourth Mg site, Mg is bonded to eight Mg and four Ti atoms to form MgMg8Ti4 cuboctahedra that share corners with six equivalent MgMg8Ti4 cuboctahedra, corners with twelve TiMg8Ti4 cuboctahedra, edges with six TiMg8Ti4 cuboctahedra, edges with twelve MgMg9Ti3 cuboctahedra, faces with six TiMg8Ti4 cuboctahedra, and faces with fourteen MgMg9Ti3 cuboctahedra. Both Mg–Mg bond lengths are 2.96 Å. All Mg–Ti bond lengths are 3.28 Å. There are two inequivalent Ti sites. In the first Ti site, Ti is bonded to eight Mg and four Ti atoms to form TiMg8Ti4 cuboctahedra that share corners with six equivalent MgMg8Ti4 cuboctahedra, corners with twelve TiMg8Ti4 cuboctahedra, edges with three equivalent TiMg8Ti4 cuboctahedra, edges with fifteen MgMg9Ti3 cuboctahedra, faces with five TiMg8Ti4 cuboctahedra, and faces with fifteen MgMg9Ti3 cuboctahedra. There are two shorter (2.74 Å) and two longer (2.96 Å) Ti–Ti bond lengths. In the second Ti site, Ti is bonded to eight Mg and four Ti atoms to form TiMg8Ti4 cuboctahedra that share corners with six equivalent MgMg8Ti4 cuboctahedra, corners with twelve TiMg8Ti4 cuboctahedra, edges with three equivalent TiMg8Ti4 cuboctahedra, edges with fifteen MgMg9Ti3 cuboctahedra, faces with five TiMg8Ti4 cuboctahedra, and faces with fifteen MgMg9Ti3 cuboctahedra. Both Ti–Ti bond lengths are 2.96 Å.