DOE OSTI2020
K3Nb3B2O12 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 2-coordinate geometry to thirteen O2- atoms. There are a spread of K–O bond distances ranging from 2.78–3.30 Å. In the second K1+ site, K1+ is bonded in a 4-coordinate geometry to thirteen O2- atoms. There are a spread of K–O bond distances ranging from 2.84–3.22 Å. In the third K1+ site, K1+ is bonded in a 4-coordinate geometry to thirteen O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.28 Å. In the fourth K1+ site, K1+ is bonded in a 2-coordinate geometry to thirteen O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.28 Å. There are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–31°. There are a spread of Nb–O bond distances ranging from 1.86–2.20 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–30°. There are a spread of Nb–O bond distances ranging from 1.86–2.20 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–29°. There are a spread of Nb–O bond distances ranging from 1.86–2.20 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–30°. There are a spread of Nb–O bond distances ranging from 1.86–2.20 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.38 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. All B–O bond lengths are 1.38 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two Nb5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two equivalent Nb5+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two equivalent Nb5+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Nb5+, and one B3+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two equivalent Nb5+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two equivalent Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two equivalent Nb5+ atoms.