Materials Data on Nb6Tl2VCl18 by Materials Project
Tl2VNb6Cl18 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Nb2+ is bonded to five Cl1- atoms to form NbCl5 square pyramids that share corners with two equivalent TlCl12 cuboctahedra, a cornercorner with one VCl6 octahedra, corners with four equivalent NbCl5 square pyramids, an edgeedge with one TlCl12 cuboctahedra, and a faceface with one TlCl12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Nb–Cl bond distances ranging from 2.47–2.69 Å. V4+ is bonded to six equivalent Cl1- atoms to form VCl6 octahedra that share corners with six equivalent TlCl12 cuboctahedra and corners with six equivalent NbCl5 square pyramids. All V–Cl bond lengths are 2.55 Å. Tl1+ is bonded to twelve Cl1- atoms to form TlCl12 cuboctahedra that share corners with three equivalent VCl6 octahedra, corners with six equivalent NbCl5 square pyramids, edges with three equivalent TlCl12 cuboctahedra, edges with three equivalent NbCl5 square pyramids, and faces with three equivalent NbCl5 square pyramids. The corner-sharing octahedral tilt angles are 51°. There are a spread of Tl–Cl bond distances ranging from 3.47–3.56 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two equivalent Nb2+ and one Tl1+ atom. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two equivalent Nb2+ and two equivalent Tl1+ atoms. In the third Cl1- site, Cl1- is bonded in a 2-coordinate geometry to one Nb2+, one V4+, and one Tl1+ atom.