Materials Data on K2NbTlF6 by Materials Project

Abstract

K2NbTlF6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent F1- atoms to form KF12 cuboctahedra that share corners with twelve equivalent KF12 cuboctahedra, faces with six equivalent KF12 cuboctahedra, faces with four equivalent NbF6 octahedra, and faces with four equivalent TlF6 octahedra. All K–F bond lengths are 3.36 Å. Nb3+ is bonded to six equivalent F1- atoms to form NbF6 octahedra that share corners with six equivalent TlF6 octahedra and faces with eight equivalent KF12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Nb–F bond lengths are 2.10 Å. Tl1+ is bonded to six equivalent F1- atoms to form TlF6 octahedra that share corners with six equivalent NbF6 octahedra and faces with eight equivalent KF12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Tl–F bond lengths are 2.64 Å. F1- is bonded in a distorted linear geometry to four equivalent K1+, one Nb3+, and one Tl1+ atom.