Materials Data on Ti5TlSe8 by Materials Project

Abstract

Ti5TlSe8 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Ti3+ sites. In the first Ti3+ site, Ti3+ is bonded to six Se2- atoms to form TiSe6 octahedra that share corners with four equivalent TiSe6 octahedra, edges with four equivalent TlSe10 cuboctahedra, and edges with six TiSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are four shorter (2.58 Å) and two longer (2.60 Å) Ti–Se bond lengths. In the second Ti3+ site, Ti3+ is bonded to six Se2- atoms to form TiSe6 octahedra that share corners with three equivalent TlSe10 cuboctahedra, corners with four equivalent TiSe6 octahedra, an edgeedge with one TlSe10 cuboctahedra, edges with six TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Ti–Se bond distances ranging from 2.50–2.76 Å. In the third Ti3+ site, Ti3+ is bonded to six Se2- atoms to form TiSe6 octahedra that share corners with four equivalent TlSe10 cuboctahedra, corners with six TiSe6 octahedra, edges with four equivalent TiSe6 octahedra, a faceface with one TlSe10 cuboctahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Ti–Se bond distances ranging from 2.51–2.67 Å. Tl1+ is bonded to ten Se2- atoms to form distorted TlSe10 cuboctahedra that share corners with fourteen TiSe6 octahedra, edges with six TiSe6 octahedra, faces with two equivalent TlSe10 cuboctahedra, and faces with two equivalent TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 13–44°. There are a spread of Tl–Se bond distances ranging from 3.48–3.59 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to four Ti3+ and one Tl1+ atom. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Ti3+ and two equivalent Tl1+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to five Ti3+ atoms. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ti3+ and two equivalent Tl1+ atoms.