Materials Data on MgTi2 by Materials Project

Abstract

MgTi2 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Mg is bonded to three equivalent Mg and nine Ti atoms to form MgMg3Ti9 cuboctahedra that share corners with four equivalent TiMg4Ti8 cuboctahedra, corners with five equivalent MgMg3Ti9 cuboctahedra, edges with two equivalent TiMg4Ti8 cuboctahedra, edges with eight equivalent MgMg3Ti9 cuboctahedra, faces with four equivalent TiMg4Ti8 cuboctahedra, and faces with five equivalent MgMg3Ti9 cuboctahedra. There are one shorter (2.85 Å) and two longer (2.94 Å) Mg–Mg bond lengths. There are a spread of Mg–Ti bond distances ranging from 2.97–3.14 Å. There are four inequivalent Ti sites. In the first Ti site, Ti is bonded to four equivalent Mg and eight Ti atoms to form TiMg4Ti8 cuboctahedra that share corners with eight equivalent MgMg3Ti9 cuboctahedra, edges with four equivalent MgMg3Ti9 cuboctahedra, edges with six equivalent TiMg4Ti8 cuboctahedra, faces with two equivalent TiMg4Ti8 cuboctahedra, and faces with eight equivalent MgMg3Ti9 cuboctahedra. There are a spread of Ti–Ti bond distances ranging from 2.84–2.94 Å. In the second Ti site, Ti is bonded in a 12-coordinate geometry to four equivalent Mg and eight Ti atoms. There are a spread of Ti–Ti bond distances ranging from 2.79–3.34 Å. In the third Ti site, Ti is bonded in a 12-coordinate geometry to six equivalent Mg and six Ti atoms. There are one shorter (2.79 Å) and one longer (3.34 Å) Ti–Ti bond lengths. In the fourth Ti site, Ti is bonded in a 12-coordinate geometry to four equivalent Mg and eight Ti atoms. There are a spread of Ti–Mg bond distances ranging from 2.97–3.10 Å. Both Ti–Ti bond lengths are 2.93 Å.