DOE OSTI2020
GdGa3(BO3)4 is Calcite-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. Gd3+ is bonded to six equivalent O2- atoms to form distorted GdO6 pentagonal pyramids that share corners with six equivalent GaO6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Gd–O bond lengths are 2.37 Å. Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent GdO6 pentagonal pyramids and edges with two equivalent GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.03 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.38 Å) and one longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.39 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ga3+ and one B3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Gd3+, one Ga3+, and one B3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ga3+ and one B3+ atom.