Materials Data on Tb2Be2O5 by Materials Project
Be2Tb2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Be2+ is bonded to five O2- atoms to form distorted BeO5 square pyramids that share corners with five equivalent BeO5 square pyramids and faces with four equivalent TbO12 cuboctahedra. There is one shorter (1.58 Å) and four longer (1.83 Å) Be–O bond length. There are two inequivalent Tb3+ sites. In the first Tb3+ site, Tb3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Tb–O bond lengths are 2.35 Å. In the second Tb3+ site, Tb3+ is bonded to twelve O2- atoms to form TbO12 cuboctahedra that share corners with four equivalent TbO12 cuboctahedra, faces with four equivalent TbO12 cuboctahedra, and faces with eight equivalent BeO5 square pyramids. There are four shorter (2.56 Å) and eight longer (2.62 Å) Tb–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Be2+ and four Tb3+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Be2+ and four equivalent Tb3+ atoms.