DOE OSTI2020
Gd2Sc3Ge4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Gd is bonded to seven Ge atoms to form distorted GdGe7 pentagonal bipyramids that share corners with four equivalent ScGe6 octahedra, corners with six equivalent GdGe7 pentagonal bipyramids, edges with two equivalent GdGe7 pentagonal bipyramids, faces with two equivalent ScGe6 octahedra, and faces with three equivalent GdGe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 45–50°. There are a spread of Gd–Ge bond distances ranging from 2.96–3.21 Å. There are two inequivalent Sc sites. In the first Sc site, Sc is bonded to six Ge atoms to form ScGe6 octahedra that share corners with four equivalent ScGe6 octahedra, corners with eight equivalent GdGe7 pentagonal bipyramids, and faces with four equivalent GdGe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Sc–Ge bond distances ranging from 2.82–2.98 Å. In the second Sc site, Sc is bonded in a 6-coordinate geometry to six Ge atoms. There are a spread of Sc–Ge bond distances ranging from 2.76–2.91 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent Gd, four Sc, and one Ge atom. The Ge–Ge bond length is 2.78 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent Gd, four Sc, and one Ge atom. The Ge–Ge bond length is 2.90 Å. In the third Ge site, Ge is bonded in a 9-coordinate geometry to two equivalent Gd, six Sc, and one Ge atom.