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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on KNa7V8O24 by Materials Project

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNa7V8O24 by Materials Project

KNa7V8O24 is Esseneite-like structured and crystallizes in the monoclinic P2 space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.63–3.24 Å. There are seven inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six VO4 tetrahedra and edges with two equivalent NaO6 octahedra. There are two shorter (2.38 Å) and four longer (2.44 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six VO4 tetrahedra and edges with two equivalent NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.39–2.46 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six VO4 tetrahedra and edges with two equivalent NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.40–2.46 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six VO4 tetrahedra and edges with two equivalent NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.39–2.45 Å. In the fifth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.48–2.77 Å. In the sixth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.49–2.78 Å. In the seventh Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.48–2.78 Å. There are four inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with three NaO6 octahedra and corners with two equivalent VO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–61°. There are a spread of V–O bond distances ranging from 1.67–1.84 Å. In the second V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with three NaO6 octahedra and corners with two equivalent VO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–58°. There are a spread of V–O bond distances ranging from 1.67–1.83 Å. In the third V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with three NaO6 octahedra and corners with two equivalent VO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–61°. There are a spread of V–O bond distances ranging from 1.67–1.83 Å. In the fourth V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with three NaO6 octahedra and corners with two equivalent VO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–61°. There are a spread of V–O bond distances ranging from 1.67–1.83 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one V5+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one K1+, two Na1+, and one V5+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one V5+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one V5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two V5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two V5+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and two V5+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two V5+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one V5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one V5+ atom. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one K1+, one Na1+, and one V5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one V5+ atom.

36 MATERIALS SCIENCE↗