Materials Data on Er2Tc2O7 by Materials Project
Er2Tc2O7 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Er3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are two shorter (2.22 Å) and six longer (2.45 Å) Er–O bond lengths. Tc4+ is bonded to six equivalent O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedral tilt angles are 54°. All Tc–O bond lengths are 2.04 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Er3+ atoms to form OEr4 tetrahedra that share corners with sixteen OEr4 tetrahedra and edges with six equivalent OEr2Tc2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Er3+ and two equivalent Tc4+ atoms to form a mixture of distorted corner and edge-sharing OEr2Tc2 tetrahedra.