Materials Data on CaTl2O4 by Materials Project

Abstract

CaTl2O4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.93 Å. 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 0–60°. There are a spread of Tl–O bond distances ranging from 2.19–2.40 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Tl3+ atoms to form OCa2Tl2 tetrahedra that share corners with two equivalent OCa2Tl2 tetrahedra, corners with ten equivalent OCa2Tl3 trigonal bipyramids, edges with four equivalent OCa2Tl4 octahedra, and edges with two equivalent OCa2Tl3 trigonal bipyramids. In the second O2- site, O2- is bonded to two equivalent Ca2+ and four equivalent Tl3+ atoms to form distorted OCa2Tl4 octahedra that share corners with two equivalent OCa2Tl4 octahedra, corners with eight equivalent OCa2Tl3 trigonal bipyramids, edges with two equivalent OCa2Tl4 octahedra, edges with four equivalent OCa2Tl2 tetrahedra, and edges with six equivalent OCa2Tl3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. In the third O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Tl3+ atoms to form distorted OCa2Tl3 trigonal bipyramids that share corners with four equivalent OCa2Tl4 octahedra, corners with five equivalent OCa2Tl2 tetrahedra, corners with two equivalent OCa2Tl3 trigonal bipyramids, edges with three equivalent OCa2Tl4 octahedra, an edgeedge with one OCa2Tl2 tetrahedra, and edges with five equivalent OCa2Tl3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 7–45°.