DOI: 10.17188/1206329
title: Materials Data on Ti19Se20 by Materials Project

description: Ti19Se20 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are eleven inequivalent Ti+2.11+ sites. In the first Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 42–45°. There are a spread of Ti–Se bond distances ranging from 2.57–2.63 Å. In the second Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 42–50°. There are a spread of Ti–Se bond distances ranging from 2.57–2.66 Å. In the third Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 43–47°. There are a spread of Ti–Se bond distances ranging from 2.57–2.64 Å. In the fourth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 42–50°. There are a spread of Ti–Se bond distances ranging from 2.59–2.67 Å. In the fifth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 43–48°. There are a spread of Ti–Se bond distances ranging from 2.57–2.65 Å. In the sixth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 42–50°. There are a spread of Ti–Se bond distances ranging from 2.57–2.66 Å. In the seventh Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 43–48°. There are a spread of Ti–Se bond distances ranging from 2.58–2.64 Å. In the eighth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There are a spread of Ti–Se bond distances ranging from 2.57–2.63 Å. In the ninth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 45–48°. There are four shorter (2.60 Å) and two longer (2.62 Å) Ti–Se bond lengths. In the tenth Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 46–48°. There are a spread of Ti–Se bond distances ranging from 2.59–2.62 Å. In the eleventh Ti+2.11+ site, Ti+2.11+ is bonded to six Se2- atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 45–46°. There are four shorter (2.57 Å) and two longer (2.62 Å) Ti–Se bond lengths. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with six SeTi6 pentagonal pyramids, edges with five SeTi6 pentagonal pyramids, and edges with three equivalent SeTi5 trigonal bipyramids. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to five Ti+2.11+ atoms. In the third Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with three SeTi6 pentagonal pyramids, edges with nine SeTi6 pentagonal pyramids, and edges with two equivalent SeTi5 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with three equivalent SeTi6 pentagonal pyramids, corners with two equivalent SeTi5 trigonal bipyramids, and edges with ten SeTi6 pentagonal pyramids. In the fifth Se2- site, Se2- is bonded to five Ti+2.11+ atoms to form distorted SeTi5 trigonal bipyramids that share corners with three SeTi6 pentagonal pyramids, corners with two equivalent SeTi5 trigonal bipyramids, and edges with eight SeTi6 pentagonal pyramids. In the sixth Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form a mixture of distorted corner and edge-sharing SeTi6 pentagonal pyramids. In the seventh Se2- site, Se2- is bonded in a 5-coordinate geometry to five Ti+2.11+ atoms. In the eighth Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with five SeTi6 pentagonal pyramids, a cornercorner with one SeTi5 trigonal bipyramid, and edges with ten SeTi6 pentagonal pyramids. In the ninth Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with five SeTi6 pentagonal pyramids, edges with nine SeTi6 pentagonal pyramids, and an edgeedge with one SeTi5 trigonal bipyramid. In the tenth Se2- site, Se2- is bonded to six Ti+2.11+ atoms to form distorted SeTi6 pentagonal pyramids that share corners with three SeTi6 pentagonal pyramids, edges with nine SeTi6 pentagonal pyramids, and edges with two equivalent SeTi5 trigonal bipyramids.