DOE OSTI2020
Yb3O4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Yb+2.67+ sites. In the first Yb+2.67+ site, Yb+2.67+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Yb–O bond distances ranging from 2.37–2.58 Å. In the second Yb+2.67+ site, Yb+2.67+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Yb–O bond distances ranging from 2.27–2.60 Å. In the third Yb+2.67+ site, Yb+2.67+ is bonded to six O2- atoms to form edge-sharing YbO6 octahedra. There are a spread of Yb–O bond distances ranging from 2.21–2.40 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to five Yb+2.67+ atoms to form distorted OYb5 square pyramids that share corners with three equivalent OYb6 octahedra, corners with six equivalent OYb5 trigonal bipyramids, edges with three equivalent OYb6 octahedra, edges with two equivalent OYb5 square pyramids, and edges with six OYb5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–29°. In the second O2- site, O2- is bonded to six Yb+2.67+ atoms to form distorted OYb6 octahedra that share corners with three equivalent OYb5 square pyramids, corners with nine OYb5 trigonal bipyramids, edges with four equivalent OYb6 octahedra, edges with three equivalent OYb5 square pyramids, edges with three equivalent OYb5 trigonal bipyramids, and a faceface with one OYb5 trigonal bipyramid. In the third O2- site, O2- is bonded to five Yb+2.67+ atoms to form distorted OYb5 trigonal bipyramids that share corners with five equivalent OYb6 octahedra, corners with seven OYb5 trigonal bipyramids, edges with three equivalent OYb6 octahedra, edges with four equivalent OYb5 square pyramids, and edges with two equivalent OYb5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 6–50°. In the fourth O2- site, O2- is bonded to five Yb+2.67+ atoms to form distorted OYb5 trigonal bipyramids that share corners with four equivalent OYb6 octahedra, corners with six equivalent OYb5 square pyramids, corners with three equivalent OYb5 trigonal bipyramids, edges with two equivalent OYb5 square pyramids, edges with six OYb5 trigonal bipyramids, and a faceface with one OYb6 octahedra. The corner-sharing octahedra tilt angles range from 57–64°.