Materials Data on K2TaNbO6 by Materials Project

Abstract

K2TaNbO6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm 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, faces with four equivalent TaO6 octahedra, and faces with four equivalent NbO6 octahedra. There are eight shorter (2.86 Å) and four longer (2.87 Å) K–O bond lengths. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent TaO6 octahedra, and faces with eight equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.01 Å) and four longer (2.03 Å) Ta–O bond lengths. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent NbO6 octahedra, and faces with eight equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.03 Å) and two longer (2.04 Å) Nb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent K1+, one Ta5+, and one Nb5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Nb5+ atoms.