Materials Data on MgTiO2 by Materials Project
MgTiO2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four equivalent TiO6 octahedra, corners with four equivalent TiO5 trigonal bipyramids, edges with two equivalent MgO5 square pyramids, an edgeedge with one TiO5 trigonal bipyramid, and a faceface with one TiO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Mg–O bond distances ranging from 2.04–2.12 Å. In the second Mg2+ site, Mg2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 2.08–2.17 Å. There are two inequivalent Ti2+ sites. In the first Ti2+ site, Ti2+ is bonded to five O2- atoms to form distorted TiO5 trigonal bipyramids that share corners with four equivalent TiO6 octahedra, corners with four equivalent MgO5 square pyramids, an edgeedge with one MgO5 square pyramid, and edges with two equivalent TiO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–48°. There are a spread of Ti–O bond distances ranging from 1.99–2.13 Å. In the second Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent MgO5 square pyramids, corners with four equivalent TiO5 trigonal bipyramids, edges with four equivalent TiO6 octahedra, and a faceface with one MgO5 square pyramid. There are a spread of Ti–O bond distances ranging from 2.19–2.24 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Ti2+ atoms to form distorted OMgTi3 tetrahedra that share a cornercorner with one OMg3Ti3 pentagonal pyramid, corners with four equivalent OMg3Ti2 square pyramids, corners with two equivalent OMgTi3 tetrahedra, corners with four equivalent OMg2Ti3 trigonal bipyramids, edges with two equivalent OMg3Ti3 pentagonal pyramids, and an edgeedge with one OMg3Ti2 square pyramid. In the second O2- site, O2- is bonded to two equivalent Mg2+ and three Ti2+ atoms to form distorted OMg2Ti3 trigonal bipyramids that share corners with two equivalent OMg3Ti3 pentagonal pyramids, corners with four equivalent OMgTi3 tetrahedra, edges with three equivalent OMg3Ti3 pentagonal pyramids, edges with two equivalent OMg3Ti2 square pyramids, and edges with two equivalent OMg2Ti3 trigonal bipyramids. In the third O2- site, O2- is bonded to three Mg2+ and two equivalent Ti2+ atoms to form OMg3Ti2 square pyramids that share corners with three equivalent OMg3Ti3 pentagonal pyramids, corners with four equivalent OMgTi3 tetrahedra, an edgeedge with one OMg3Ti3 pentagonal pyramid, edges with two equivalent OMg3Ti2 square pyramids, an edgeedge with one OMgTi3 tetrahedra, and edges with two equivalent OMg2Ti3 trigonal bipyramids. In the fourth O2- site, O2- is bonded to three Mg2+ and three equivalent Ti2+ atoms to form distorted OMg3Ti3 pentagonal pyramids that share corners with three equivalent OMg3Ti2 square pyramids, a cornercorner with one OMgTi3 tetrahedra, corners with two equivalent OMg2Ti3 trigonal bipyramids, edges with four equivalent OMg3Ti3 pentagonal pyramids, an edgeedge with one OMg3Ti2 square pyramid, edges with two equivalent OMgTi3 tetrahedra, and edges with three equivalent OMg2Ti3 trigonal bipyramids.