Materials Data on Rb2U2O7 by Materials Project

Rb2U2O7 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to six O2- atoms to form RbO6 octahedra that share corners with four equivalent UO6 octahedra and edges with six RbO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Rb–O bond distances ranging from 2.81–2.89 Å. In the second Rb1+ site, Rb1+ is bonded to six O2- atoms to form distorted RbO6 octahedra that share corners with two equivalent UO6 octahedra and edges with six RbO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Rb–O bond distances ranging from 2.91–2.94 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 1.86–2.56 Å. In the second U6+ site, U6+ is bonded to six O2- atoms to form distorted UO6 octahedra that share corners with two equivalent UO6 octahedra and corners with six RbO6 octahedra. The corner-sharing octahedra tilt angles range from 40–57°. There are a spread of U–O bond distances ranging from 1.91–2.30 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Rb1+ and one U6+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Rb1+ and one U6+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Rb1+ and one U6+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Rb1+ and one U6+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three U6+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three U6+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three U6+ atoms.