Materials Data on Cs2Ta6PbCl18 by Materials Project

Abstract

Cs2PbTa6Cl18 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Cs is bonded to twelve Cl atoms to form CsCl12 cuboctahedra that share corners with three equivalent PbCl6 octahedra, corners with six equivalent TaCl5 square pyramids, edges with three equivalent CsCl12 cuboctahedra, edges with three equivalent TaCl5 square pyramids, and faces with three equivalent TaCl5 square pyramids. The corner-sharing octahedral tilt angles are 56°. There are a spread of Cs–Cl bond distances ranging from 3.59–3.78 Å. Ta is bonded to five Cl atoms to form distorted TaCl5 square pyramids that share corners with two equivalent CsCl12 cuboctahedra, a cornercorner with one PbCl6 octahedra, corners with four equivalent TaCl5 square pyramids, an edgeedge with one CsCl12 cuboctahedra, and a faceface with one CsCl12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Ta–Cl bond distances ranging from 2.47–2.65 Å. Pb is bonded to six equivalent Cl atoms to form PbCl6 octahedra that share corners with six equivalent CsCl12 cuboctahedra and corners with six equivalent TaCl5 square pyramids. All Pb–Cl bond lengths are 2.97 Å. There are three inequivalent Cl sites. In the first Cl site, Cl is bonded in a 3-coordinate geometry to one Cs and two equivalent Ta atoms. In the second Cl site, Cl is bonded in a 3-coordinate geometry to one Cs, one Ta, and one Pb atom. In the third Cl site, Cl is bonded in a 4-coordinate geometry to two equivalent Cs and two equivalent Ta atoms.