Materials Data on Er2SeO2 by Materials Project

Er2SeO2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Er3+ is bonded in a 4-coordinate geometry to three equivalent Se2- and four equivalent O2- atoms. All Er–Se bond lengths are 2.96 Å. All Er–O bond lengths are 2.27 Å. Se2- is bonded to six equivalent Er3+ atoms to form distorted SeEr6 octahedra that share corners with twelve equivalent OEr4 tetrahedra, edges with six equivalent SeEr6 octahedra, and edges with six equivalent OEr4 tetrahedra. O2- is bonded to four equivalent Er3+ atoms to form OEr4 tetrahedra that share corners with six equivalent SeEr6 octahedra, corners with six equivalent OEr4 tetrahedra, edges with three equivalent SeEr6 octahedra, and edges with three equivalent OEr4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–48°.