Materials Data on U2Bi2O7 by Materials Project
U2Bi2O7 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.23–2.36 Å. In the second U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.24–2.34 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are four shorter (2.43 Å) and two longer (2.56 Å) Bi–O bond lengths. In the second Bi3+ site, Bi3+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are two shorter (2.32 Å) and four longer (2.59 Å) Bi–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent U4+ and two equivalent Bi3+ atoms to form distorted OU2Bi2 tetrahedra that share corners with fourteen OU2Bi2 tetrahedra and edges with five OUBi3 tetrahedra. In the second O2- site, O2- is bonded to one U4+ and three Bi3+ atoms to form a mixture of edge and corner-sharing OUBi3 tetrahedra. In the third O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the fourth O2- site, O2- is bonded to three U4+ and one Bi3+ atom to form distorted OU3Bi tetrahedra that share corners with fourteen OU2Bi2 tetrahedra and edges with six OUBi3 tetrahedra. In the fifth O2- site, O2- is bonded to two equivalent U4+ and two equivalent Bi3+ atoms to form distorted OU2Bi2 tetrahedra that share corners with fourteen OUBi3 tetrahedra and edges with five OU4 tetrahedra.