Materials Data on Sm4(GeO5)3 by Materials Project

Sm4(GeO5)3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded to eight O atoms to form distorted SmO8 pentagonal bipyramids that share corners with two equivalent GeO4 tetrahedra and edges with three equivalent SmO8 pentagonal bipyramids. There are a spread of Sm–O bond distances ranging from 2.31–2.88 Å. In the second Sm site, Sm is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Sm–O bond distances ranging from 2.33–2.91 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded to four O atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two equivalent SmO8 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 57°. There is two shorter (1.76 Å) and two longer (1.79 Å) Ge–O bond length. In the second Ge site, Ge is bonded to six O atoms to form GeO6 octahedra that share corners with two equivalent GeO6 octahedra and corners with four equivalent GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There is four shorter (1.93 Å) and two longer (1.94 Å) Ge–O bond length. There are seven inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to two Sm and one Ge atom. In the second O site, O is bonded in a distorted trigonal planar geometry to two Sm and one Ge atom. In the third O site, O is bonded to two equivalent Sm and two equivalent Ge atoms to form distorted corner-sharing OSm2Ge2 tetrahedra. In the fourth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Sm atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two equivalent Sm atoms. In the sixth O site, O is bonded in a rectangular see-saw-like geometry to four Sm atoms. In the seventh O site, O is bonded in a distorted trigonal planar geometry to one Sm and two Ge atoms.