Materials Data on BaU2O7 by Materials Project
BaU2O7 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ba–O bond lengths are 2.91 Å. In the second Ba2+ site, Ba2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ba–O bond lengths are 2.91 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of U–O bond distances ranging from 1.90–2.36 Å. In the second U6+ site, U6+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of U–O bond distances ranging from 1.90–2.36 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four U6+ atoms to form corner-sharing OU4 tetrahedra. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent U6+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one U6+ atom.