Materials Data on Sm2Au2O5 by Materials Project

Abstract

Sm2Au2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Sm–O bond lengths are 2.66 Å. In the second Sm3+ site, Sm3+ is bonded to twelve O2- atoms to form SmO12 cuboctahedra that share corners with four equivalent SmO12 cuboctahedra, faces with four equivalent SmO12 cuboctahedra, and faces with eight equivalent AuO5 square pyramids. There are eight shorter (2.87 Å) and four longer (2.98 Å) Sm–O bond lengths. Au2+ is bonded to five O2- atoms to form AuO5 square pyramids that share corners with five equivalent AuO5 square pyramids and faces with four equivalent SmO12 cuboctahedra. There are four shorter (2.12 Å) and one longer (2.20 Å) Au–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four Sm3+ and two equivalent Au2+ atoms to form a mixture of distorted face, edge, and corner-sharing OSm4Au2 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sm3+ and two equivalent Au2+ atoms.