Materials Data on CaGd2O4 by Materials Project

Abstract

CaGd2O4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.30 Å) and four longer (2.65 Å) Ca–O bond lengths. Gd3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing GdO6 octahedra. The corner-sharing octahedra tilt angles range from 0–62°. There are a spread of Gd–O bond distances ranging from 2.26–2.40 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted square co-planar geometry to four equivalent Gd3+ atoms. In the second O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Gd3+ atoms to form distorted OCa2Gd3 trigonal bipyramids that share corners with five equivalent OCa2Gd2 tetrahedra, corners with two equivalent OCa2Gd3 trigonal bipyramids, an edgeedge with one OCa2Gd2 tetrahedra, and edges with five equivalent OCa2Gd3 trigonal bipyramids. In the third O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Gd3+ atoms to form OCa2Gd2 tetrahedra that share corners with two equivalent OCa2Gd2 tetrahedra, corners with ten equivalent OCa2Gd3 trigonal bipyramids, and edges with two equivalent OCa2Gd3 trigonal bipyramids.