Materials Data on RbTi5Se8 by Materials Project
RbTi5Se8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Rb1+ is bonded in a 10-coordinate geometry to ten Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.56–3.63 Å. There are three inequivalent Ti3+ sites. In the first Ti3+ site, Ti3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles are 49°. All Ti–Se bond lengths are 2.60 Å. In the second Ti3+ site, Ti3+ is bonded to six Se2- atoms to form a mixture of face, edge, and corner-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Ti–Se bond distances ranging from 2.52–2.73 Å. In the third Ti3+ site, Ti3+ is bonded to six Se2- atoms to form a mixture of face, edge, and corner-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–53°. There are a spread of Ti–Se bond distances ranging from 2.53–2.67 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Rb1+ and four Ti3+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Rb1+ and three Ti3+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Rb1+ and three equivalent Ti3+ atoms. In the fourth Se2- site, Se2- is bonded to five Ti3+ atoms to form distorted edge-sharing SeTi5 square pyramids.