Materials Data on K2NaTiOF5 by Materials Project

Abstract

K2NaTiOF5 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. K1+ is bonded to two equivalent O2- and ten F1- atoms to form KO2F10 cuboctahedra that share corners with twelve equivalent KO2F10 cuboctahedra, faces with six equivalent KO2F10 cuboctahedra, faces with four equivalent NaOF5 octahedra, and faces with four equivalent TiOF5 octahedra. Both K–O bond lengths are 3.00 Å. There are a spread of K–F bond distances ranging from 2.96–3.05 Å. Na1+ is bonded to one O2- and five F1- atoms to form NaOF5 octahedra that share corners with six equivalent TiOF5 octahedra and faces with eight equivalent KO2F10 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–7°. The Na–O bond length is 2.37 Å. There are four shorter (2.28 Å) and one longer (2.29 Å) Na–F bond lengths. Ti4+ is bonded to one O2- and five F1- atoms to form TiOF5 octahedra that share corners with six equivalent NaOF5 octahedra and faces with eight equivalent KO2F10 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–7°. The Ti–O bond length is 1.72 Å. There are four shorter (1.96 Å) and one longer (2.13 Å) Ti–F bond lengths. O2- is bonded in a 2-coordinate geometry to four equivalent K1+, one Na1+, and one Ti4+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted linear geometry to four equivalent K1+, one Na1+, and one Ti4+ atom. In the second F1- site, F1- is bonded in a distorted linear geometry to four equivalent K1+, one Na1+, and one Ti4+ atom.