DOI: 10.17188/1731406
title: Materials Data on Ca3Tl4O9 by Materials Project

description: Ca3Tl4O9 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.72 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.86 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three TlO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with five TlO6 octahedra. The corner-sharing octahedra tilt angles range from 12–63°. There are a spread of Ca–O bond distances ranging from 2.26–2.47 Å. There are four inequivalent Tl3+ sites. In the first Tl3+ site, Tl3+ is bonded to six O2- atoms to form TlO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with two equivalent TlO6 octahedra, and edges with five TlO6 octahedra. The corner-sharing octahedra tilt angles range from 4–63°. There are a spread of Tl–O bond distances ranging from 2.13–2.44 Å. In the second Tl3+ site, Tl3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TlO6 octahedra. The corner-sharing octahedra tilt angles range from 4–60°. There are a spread of Tl–O bond distances ranging from 2.19–2.44 Å. In the third Tl3+ site, Tl3+ is bonded to six O2- atoms to form TlO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with two equivalent TlO6 octahedra, edges with three equivalent CaO6 octahedra, and edges with five TlO6 octahedra. The corner-sharing octahedra tilt angles range from 4–12°. There are a spread of Tl–O bond distances ranging from 2.15–2.47 Å. In the fourth Tl3+ site, Tl3+ is bonded to six O2- atoms to form TlO6 octahedra that share corners with three TlO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with five TlO6 octahedra. The corner-sharing octahedra tilt angles range from 4–60°. There are a spread of Tl–O bond distances ranging from 2.19–2.40 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and three Tl3+ atoms to form distorted OCa2Tl3 trigonal bipyramids that share corners with two equivalent OCa2Tl4 octahedra, corners with five OCa3Tl tetrahedra, corners with two equivalent OCa2Tl3 trigonal bipyramids, edges with three equivalent OCa2Tl4 octahedra, edges with two equivalent OCa2Tl3 square pyramids, an edgeedge with one OCa2Tl2 tetrahedra, and edges with three OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 5°. In the second O2- site, O2- is bonded to two equivalent Ca2+ and three Tl3+ atoms to form distorted OCa2Tl3 square pyramids that share corners with two equivalent OCa2Tl4 octahedra, corners with five OCa3Tl tetrahedra, edges with three equivalent OCa2Tl4 octahedra, edges with two equivalent OCa2Tl3 square pyramids, an edgeedge with one OCa3Tl tetrahedra, and edges with two equivalent OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 10°. In the third O2- site, O2- is bonded to three Ca2+ and one Tl3+ atom to form OCa3Tl tetrahedra that share corners with seven OCa2Tl3 square pyramids, corners with two equivalent OCa3Tl tetrahedra, a cornercorner with one OCa2Tl3 trigonal bipyramid, edges with two equivalent OCa2Tl4 octahedra, and an edgeedge with one OCa2Tl3 square pyramid. In the fourth O2- site, O2- is bonded to two equivalent Ca2+ and two Tl3+ atoms to form OCa2Tl2 tetrahedra that share corners with four OCa2Tl3 square pyramids, corners with two equivalent OCa2Tl2 tetrahedra, corners with eight OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, and edges with two OCa2Tl3 trigonal bipyramids. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and three Tl3+ atoms to form distorted OCa2Tl3 trigonal bipyramids that share corners with two equivalent OCa2Tl4 octahedra, corners with four equivalent OCaTl4 square pyramids, corners with four equivalent OCa2Tl2 tetrahedra, corners with two equivalent OCa2Tl3 trigonal bipyramids, edges with three OCaTl4 square pyramids, an edgeedge with one OCa2Tl2 tetrahedra, and edges with three OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 42°. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to four Ca2+ and one Tl3+ atom. In the seventh O2- site, O2- is bonded to one Ca2+ and four Tl3+ atoms to form OCaTl4 square pyramids that share corners with two equivalent OCa2Tl3 square pyramids, corners with three OCa3Tl tetrahedra, corners with four equivalent OCa2Tl3 trigonal bipyramids, edges with five OCaTl4 square pyramids, and an edgeedge with one OCa2Tl3 trigonal bipyramid. In the eighth O2- site, O2- is bonded to two equivalent Ca2+ and three Tl3+ atoms to form OCa2Tl3 square pyramids that share corners with two equivalent OCaTl4 square pyramids, corners with three OCa3Tl tetrahedra, edges with five OCaTl4 square pyramids, and edges with two equivalent OCa2Tl3 trigonal bipyramids. In the ninth O2- site, O2- is bonded to two Ca2+ and four Tl3+ atoms to form OCa2Tl4 octahedra that share corners with two equivalent OCa2Tl3 square pyramids, corners with four OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, edges with three equivalent OCa2Tl3 square pyramids, edges with four OCa3Tl tetrahedra, and edges with three equivalent OCa2Tl3 trigonal bipyramids.