Materials Data on Ho2TiO5 by Materials Project

Abstract

Ho2TiO5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho3+ is bonded to six O2- atoms to form distorted HoO6 pentagonal pyramids that share a cornercorner with one TiO6 octahedra, corners with three equivalent HoO6 pentagonal pyramids, edges with three equivalent TiO6 octahedra, and edges with three equivalent HoO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 30°. There are a spread of Ho–O bond distances ranging from 2.18–2.38 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent HoO6 pentagonal pyramids, and edges with six equivalent HoO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 33°. There are a spread of Ti–O bond distances ranging from 1.88–2.12 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ho3+ and one Ti4+ atom. In the second O2- site, O2- is bonded to three equivalent Ho3+ and one Ti4+ atom to form distorted OHo3Ti trigonal pyramids that share a cornercorner with one OHo2Ti2 tetrahedra, corners with three equivalent OHo3Ti trigonal pyramids, edges with two equivalent OHo2Ti2 tetrahedra, and edges with two equivalent OHo3Ti trigonal pyramids. In the third O2- site, O2- is bonded to two equivalent Ho3+ and two equivalent Ti4+ atoms to form distorted OHo2Ti2 tetrahedra that share corners with two equivalent OHo2Ti2 tetrahedra, corners with two equivalent OHo3Ti trigonal pyramids, and edges with four equivalent OHo3Ti trigonal pyramids.