Materials Data on U2P2O9 by Materials Project
U2O(PO4)2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. U4+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO7 pentagonal bipyramid, corners with four equivalent PO4 tetrahedra, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one PO4 tetrahedra. There are a spread of U–O bond distances ranging from 2.09–2.52 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent UO7 pentagonal bipyramids and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to one U4+ and one P5+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent U4+ atoms. 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 1-coordinate geometry to two equivalent U4+ and one P5+ atom.