Materials Data on YAlGeO5 by Materials Project
YAlGeO5 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.30–2.51 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four equivalent GeO5 square pyramids and edges with two equivalent AlO6 octahedra. There is four shorter (1.90 Å) and two longer (1.95 Å) Al–O bond length. Ge4+ is bonded to five O2- atoms to form distorted GeO5 square pyramids that share corners with four equivalent AlO6 octahedra and an edgeedge with one GeO5 square pyramid. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Ge–O bond distances ranging from 1.78–1.93 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Y3+ and two equivalent Al3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Y3+, one Al3+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded to two equivalent Y3+ and two equivalent Ge4+ atoms to form distorted edge-sharing OY2Ge2 tetrahedra.