DOI: 10.17188/1654352
title: Materials Data on Ca2Tl2O5 by Materials Project

description: Ca2Tl2O5 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two 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 2.33–2.84 Å. In the second 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 14–63°. There are a spread of Ca–O bond distances ranging from 2.26–2.48 Å. There are two inequivalent Tl3+ sites. In the first 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 2–14°. There are a spread of Tl–O bond distances ranging from 2.17–2.44 Å. In the second 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, edges with two equivalent CaO6 octahedra, and edges with five TlO6 octahedra. The corner-sharing octahedra tilt angles range from 2–63°. There are a spread of Tl–O bond distances ranging from 2.14–2.42 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ca2+ and one Tl3+ atom to form OCa3Tl tetrahedra that share a cornercorner with one OCa2Tl4 octahedra, corners with three equivalent OCa2Tl3 square pyramids, corners with two equivalent OCa3Tl tetrahedra, corners with eight OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, and edges with two OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 9°. In the second 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 OCa3Tl tetrahedra, corners with three equivalent OCa4Tl trigonal bipyramids, edges with three equivalent OCa2Tl4 octahedra, edges with two equivalent OCa2Tl3 square pyramids, an edgeedge with one OCa3Tl tetrahedra, and edges with three OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 11°. In the third O2- site, O2- is bonded to four Ca2+ and one Tl3+ atom to form distorted OCa4Tl trigonal bipyramids that share corners with two equivalent OCa2Tl4 octahedra, corners with four equivalent OCa2Tl3 square pyramids, corners with four equivalent OCa3Tl tetrahedra, corners with three equivalent OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, an edgeedge with one OCa2Tl3 square pyramid, an edgeedge with one OCa3Tl tetrahedra, and edges with three OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 43°. In the fourth 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, a cornercorner with one OCa3Tl tetrahedra, corners with four OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, edges with three equivalent OCa2Tl3 square pyramids, edges with two equivalent OCa3Tl tetrahedra, and edges with five OCa2Tl3 trigonal bipyramids. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and three Tl3+ atoms to form OCa2Tl3 square pyramids that share corners with two equivalent OCa2Tl4 octahedra, corners with three equivalent OCa3Tl tetrahedra, corners with four equivalent OCa4Tl trigonal bipyramids, edges with three equivalent OCa2Tl4 octahedra, edges with two equivalent OCa2Tl3 square pyramids, and edges with three OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°.