Materials Data on Ho2Pa2O5 by Materials Project

Abstract

Pa2Ho2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pa sites. In the first Pa site, Pa is bonded in a body-centered cubic geometry to eight equivalent O atoms. All Pa–O bond lengths are 2.85 Å. In the second Pa site, Pa is bonded to twelve O atoms to form PaO12 cuboctahedra that share corners with four equivalent PaO12 cuboctahedra, faces with four equivalent PaO12 cuboctahedra, and faces with eight equivalent HoO5 square pyramids. There are eight shorter (2.90 Å) and four longer (3.08 Å) Pa–O bond lengths. Ho is bonded to five O atoms to form HoO5 square pyramids that share corners with five equivalent HoO5 square pyramids and faces with four equivalent PaO12 cuboctahedra. There are one shorter (2.08 Å) and four longer (2.18 Å) Ho–O bond lengths. There are two inequivalent O sites. In the first O site, O is bonded to four Pa and two equivalent Ho atoms to form a mixture of distorted corner, edge, and face-sharing OHo2Pa4 octahedra. The corner-sharing octahedra tilt angles range from 0–65°. In the second O site, O is bonded in a linear geometry to four equivalent Pa and two equivalent Ho atoms.