DOI: 10.17188/1308754
title: Materials Data on BaGa12O19 by Materials Project

description: BaGa12O19 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, edges with six GaO6 octahedra, edges with three equivalent GaO5 trigonal bipyramids, and faces with six GaO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.88–2.95 Å. There are eight inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent GaO6 octahedra, corners with three GaO4 tetrahedra, a cornercorner with one GaO5 trigonal bipyramid, an edgeedge with one BaO12 cuboctahedra, and edges with five GaO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Ga–O bond distances ranging from 1.92–2.10 Å. In the second Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent GaO6 octahedra, corners with three GaO4 tetrahedra, a cornercorner with one GaO5 trigonal bipyramid, an edgeedge with one BaO12 cuboctahedra, and edges with five GaO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ga–O bond distances ranging from 1.92–2.12 Å. In the third Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six equivalent GaO6 octahedra, corners with three equivalent GaO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one GaO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are three shorter (1.98 Å) and three longer (2.08 Å) Ga–O bond lengths. In the fourth Ga3+ site, Ga3+ is bonded to four O2- atoms to form corner-sharing GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. All Ga–O bond lengths are 1.91 Å. In the fifth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six GaO4 tetrahedra and edges with six GaO6 octahedra. There is three shorter (1.99 Å) and three longer (2.00 Å) Ga–O bond length. In the sixth Ga3+ site, Ga3+ is bonded to four O2- atoms to form corner-sharing GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. There is three shorter (1.90 Å) and one longer (1.92 Å) Ga–O bond length. In the seventh Ga3+ site, Ga3+ is bonded to five O2- atoms to form distorted GaO5 trigonal bipyramids that share corners with twelve GaO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of Ga–O bond distances ranging from 1.87–2.59 Å. In the eighth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six equivalent GaO6 octahedra, corners with three equivalent GaO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one GaO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are three shorter (1.97 Å) and three longer (2.11 Å) Ga–O bond lengths. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted tetrahedral geometry to four Ga3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to four Ga3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ga3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ga3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ga3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ga3+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ga3+ atoms. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Ga3+ atoms. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ga3+ atoms.