Materials Data on Gd2Mg2O5 by Materials Project

Abstract

Mg2Gd2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with five equivalent MgO5 square pyramids and faces with four equivalent GdO12 cuboctahedra. There is one shorter (1.90 Å) and four longer (1.97 Å) Mg–O bond length. There are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Gd–O bond lengths are 2.44 Å. In the second Gd3+ site, Gd3+ is bonded to twelve O2- atoms to form GdO12 cuboctahedra that share corners with four equivalent GdO12 cuboctahedra, faces with four equivalent GdO12 cuboctahedra, and faces with eight equivalent MgO5 square pyramids. There are four shorter (2.76 Å) and eight longer (2.93 Å) Gd–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+ and four Gd3+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two equivalent Mg2+ and four equivalent Gd3+ atoms.