Materials Data on KNbO3 by Materials Project

Abstract

KNbO3 is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent 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 2.80–3.00 Å. Nb5+ is bonded to six equivalent O2- atoms to form NbO6 octahedra that share corners with six equivalent NbO6 octahedra and faces with eight equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 10°. There are three shorter (1.91 Å) and three longer (2.19 Å) Nb–O bond lengths. O2- is bonded in a 2-coordinate geometry to four equivalent K1+ and two equivalent Nb5+ atoms.