Materials Data on K2U2O5 by Materials Project

Abstract

K2U2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All K–O bond lengths are 2.91 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, and faces with eight equivalent UO5 square pyramids. There are four shorter (3.08 Å) and eight longer (3.23 Å) K–O bond lengths. U4+ is bonded to five O2- atoms to form UO5 square pyramids that share corners with five equivalent UO5 square pyramids and faces with four equivalent KO12 cuboctahedra. There are one shorter (2.16 Å) and four longer (2.19 Å) U–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four K1+ and two equivalent U4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent U4+ atoms.