Materials Data on U2Ga2O5 by Materials Project

Abstract

U2Ga2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent U3+ sites. In the first U3+ site, U3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All U–O bond lengths are 2.59 Å. In the second U3+ site, U3+ is bonded to twelve O2- atoms to form UO12 cuboctahedra that share corners with four equivalent UO12 cuboctahedra, faces with four equivalent UO12 cuboctahedra, and faces with eight equivalent GaO5 square pyramids. There are eight shorter (2.69 Å) and four longer (2.85 Å) U–O bond lengths. Ga2+ is bonded to five O2- atoms to form GaO5 square pyramids that share corners with five equivalent GaO5 square pyramids and faces with four equivalent UO12 cuboctahedra. There are one shorter (1.98 Å) and four longer (2.02 Å) Ga–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four U3+ and two equivalent Ga2+ atoms to form a mixture of distorted corner, edge, and face-sharing OU4Ga2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the second O2- site, O2- is bonded in a linear geometry to four equivalent U3+ and two equivalent Ga2+ atoms.