Materials Data on KNa7V8O24 by Materials Project

Abstract

KNa7V8O24 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Pm-3m 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 NaO12 cuboctahedra, faces with six equivalent NaO12 cuboctahedra, and faces with eight equivalent VO6 octahedra. All K–O bond lengths are 2.69 Å. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve NaO12 cuboctahedra, faces with two equivalent KO12 cuboctahedra, faces with four equivalent NaO12 cuboctahedra, and faces with eight equivalent VO6 octahedra. All Na–O bond lengths are 2.67 Å. In the second Na1+ site, Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with eight equivalent NaO12 cuboctahedra, faces with six NaO12 cuboctahedra, and faces with eight equivalent VO6 octahedra. There are four shorter (2.65 Å) and eight longer (2.67 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded to twelve equivalent O2- atoms to form NaO12 cuboctahedra that share corners with twelve equivalent NaO12 cuboctahedra, faces with six equivalent NaO12 cuboctahedra, and faces with eight equivalent VO6 octahedra. All Na–O bond lengths are 2.67 Å. V5+ is bonded to six O2- atoms to form VO6 octahedra that share corners with six equivalent VO6 octahedra, a faceface with one KO12 cuboctahedra, and faces with seven NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. All V–O bond lengths are 1.89 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Na1+, and two equivalent V5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four Na1+ and two equivalent V5+ atoms.