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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on K3NbO8 by Materials Project

K3NbO8 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 4-coordinate geometry to four equivalent O atoms. All K–O bond lengths are 2.72 Å. In the second K site, K is bonded to eight O atoms to form KO8 hexagonal bipyramids that share corners with four equivalent NbO8 hexagonal bipyramids, corners with four equivalent OK3NbO trigonal bipyramids, and edges with two equivalent NbO8 hexagonal bipyramids. There are four shorter (2.82 Å) and four longer (2.88 Å) K–O bond lengths. Nb is bonded to eight O atoms to form distorted NbO8 hexagonal bipyramids that share corners with four equivalent KO8 hexagonal bipyramids, corners with four equivalent OK3NbO trigonal bipyramids, and edges with two equivalent KO8 hexagonal bipyramids. There are four shorter (2.04 Å) and four longer (2.09 Å) Nb–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one K, one Nb, and one O atom. The O–O bond length is 1.50 Å. In the second O site, O is bonded to three K, one Nb, and one O atom to form distorted OK3NbO trigonal bipyramids that share a cornercorner with one KO8 hexagonal bipyramid, a cornercorner with one NbO8 hexagonal bipyramid, corners with ten equivalent OK3NbO trigonal bipyramids, and an edgeedge with one OK3NbO trigonal bipyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNb3O8 by Materials Project

KNb3O8 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded to six O2- atoms to form distorted face-sharing KO6 pentagonal pyramids. There are four shorter (2.80 Å) and two longer (2.96 Å) K–O bond lengths. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.84–2.35 Å. In the second Nb5+ site, Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.78–2.51 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to four Nb5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one Nb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNbO3 by Materials Project

KNbO3 is (Cubic) Perovskite structured and crystallizes in the tetragonal P4mm 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 2.82–3.02 Å. Nb5+ is bonded to six O2- atoms to form distorted 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 0–12°. There are a spread of Nb–O bond distances ranging from 1.86–2.36 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent K1+ and two equivalent Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNbO3 by Materials Project

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2NbO6 by Materials Project

K2NbO6 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. K is bonded to twelve O atoms to form KO12 cuboctahedra that share corners with twelve equivalent KO12 cuboctahedra, faces with six equivalent KO12 cuboctahedra, and faces with four equivalent NbO6 octahedra. There are a spread of K–O bond distances ranging from 2.96–3.14 Å. Nb is bonded to six O atoms to form NbO6 octahedra that share faces with eight equivalent KO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 1.93–2.03 Å. There are three inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to four equivalent K and one Nb atom. In the second O site, O is bonded in a distorted single-bond geometry to four equivalent K and one Nb atom. In the third O site, O is bonded in a distorted single-bond geometry to four equivalent K and one Nb atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNbO3 by Materials Project

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4Nb15O24 by Materials Project

K4Nb15O24 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, faces with four KO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are a spread of K–O bond distances ranging from 2.91–2.97 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, faces with four KO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are four shorter (2.92 Å) and eight longer (2.95 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four KO12 cuboctahedra, faces with four KO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are a spread of K–O bond distances ranging from 2.90–2.99 Å. There are five inequivalent Nb+2.93+ sites. In the first Nb+2.93+ site, Nb+2.93+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with five NbO5 square pyramids and faces with four KO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 1.95–2.15 Å. In the second Nb+2.93+ site, Nb+2.93+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.01–2.13 Å. In the third Nb+2.93+ site, Nb+2.93+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with five NbO5 square pyramids and faces with four KO12 cuboctahedra. There are two shorter (2.07 Å) and three longer (2.11 Å) Nb–O bond lengths. In the fourth Nb+2.93+ site, Nb+2.93+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.07 Å) and two longer (2.13 Å) Nb–O bond lengths. In the fifth Nb+2.93+ site, Nb+2.93+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.07–2.14 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent K1+ and three Nb+2.93+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to two K1+ and three Nb+2.93+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four K1+ and two Nb+2.93+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two K1+ and three Nb+2.93+ atoms. In the fifth O2- site, O2- is bonded in a square co-planar geometry to four Nb+2.93+ atoms. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to two K1+ and three Nb+2.93+ atoms. In the seventh O2- site, O2- is bonded in a T-shaped geometry to three Nb+2.93+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to two K1+ and three Nb+2.93+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two K1+ and two equivalent Nb+2.93+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNbO3 by Materials Project

KNbO3 is (Cubic) Perovskite 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 KO12 cuboctahedra, faces with six equivalent KO12 cuboctahedra, and faces with eight equivalent NbO6 octahedra. All K–O bond lengths are 2.87 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 0°. All Nb–O bond lengths are 2.03 Å. O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Nb5+ atoms.

36 MATERIALS SCIENCE↗