DOI: 10.17188/1697278
title: Materials Data on Yb4Al2O9 by Materials Project

description: Yb4Al2O9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Yb3+ sites. In the first Yb3+ site, Yb3+ is bonded to six O2- atoms to form YbO6 octahedra that share corners with five AlO4 tetrahedra. There are a spread of Yb–O bond distances ranging from 2.26–2.45 Å. In the second Yb3+ site, Yb3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Yb–O bond distances ranging from 2.27–2.67 Å. In the third Yb3+ site, Yb3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Yb–O bond distances ranging from 2.27–2.78 Å. In the fourth Yb3+ site, Yb3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Yb–O bond distances ranging from 2.29–2.61 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent YbO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–52°. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent YbO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Al–O bond distances ranging from 1.75–1.79 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Yb3+ and one Al3+ atom. In the second O2- site, O2- is bonded to four Yb3+ atoms to form distorted OYb4 tetrahedra that share corners with five OYb3Al tetrahedra, corners with two equivalent OYb3Al trigonal pyramids, edges with two OYb4 tetrahedra, and an edgeedge with one OYb3Al trigonal pyramid. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Yb3+ and one Al3+ atom. In the fourth O2- site, O2- is bonded to three Yb3+ and one Al3+ atom to form distorted OYb3Al tetrahedra that share corners with six OYb4 tetrahedra, a cornercorner with one OYb3Al trigonal pyramid, an edgeedge with one OYb2Al2 tetrahedra, and an edgeedge with one OYb3Al trigonal pyramid. In the fifth O2- site, O2- is bonded to two Yb3+ and two Al3+ atoms to form distorted OYb2Al2 tetrahedra that share corners with three OYb4 tetrahedra, edges with two OYb4 tetrahedra, and an edgeedge with one OYb3Al trigonal pyramid. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Yb3+ and one Al3+ atom. In the seventh O2- site, O2- is bonded to three Yb3+ and one Al3+ atom to form distorted OYb3Al trigonal pyramids that share corners with six OYb4 tetrahedra and edges with three OYb2Al2 tetrahedra. In the eighth O2- site, O2- is bonded to four Yb3+ atoms to form distorted OYb4 tetrahedra that share corners with six OYb4 tetrahedra, corners with three equivalent OYb3Al trigonal pyramids, and edges with three OYb4 tetrahedra. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Yb3+ and one Al3+ atom.