Materials Data on UP2O7 by Materials Project

Abstract

UP2O7 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. U4+ is bonded to six O2- atoms to form UO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of U–O bond distances ranging from 2.23–2.26 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent UO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 3–14°. There is three shorter (1.53 Å) and one longer (1.59 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent UO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–12°. There is three shorter (1.53 Å) and one longer (1.59 Å) P–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to one U4+ and one P5+ atom. In the third O2- site, O2- is bonded in a linear geometry to one U4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to one U4+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a linear geometry to one U4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a linear geometry to one U4+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one U4+ and one P5+ atom.