Materials Data on CaTm2O4 by Materials Project

Abstract

CaTm2O4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.50–2.77 Å. There are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TmO6 octahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Tm–O bond distances ranging from 2.16–2.33 Å. In the second Tm3+ site, Tm3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing TmO6 octahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Tm–O bond distances ranging from 2.19–2.29 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+ and three Tm3+ atoms. In the second O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Tm3+ atoms to form a mixture of distorted edge and corner-sharing OCa2Tm3 trigonal bipyramids. In the third O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Tm3+ atoms to form a mixture of edge and corner-sharing OCa2Tm3 square pyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+ and three Tm3+ atoms.