Materials Data on KNbO3 by Materials Project

Abstract

KNbO3 is (Cubic) Perovskite structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with twelve equivalent KO12 cuboctahedra, faces with six equivalent KO12 cuboctahedra, and faces with eight equivalent NbO6 octahedra. There are a spread of K–O bond distances ranging from 2.78–3.08 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six equivalent NbO6 octahedra and faces with eight equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 8–14°. There are a spread of Nb–O bond distances ranging from 1.89–2.25 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent K1+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent K1+ and two equivalent Nb5+ atoms.