Figure 8
The [(UO2)24(CO3)30O4(OH)12(H2O)8]32− cluster in ewingite (a), its skeletal representation (b), the U core (c; the U⋯U contacts shorter than 4 Å are shown as thick black lines; those between 4 and 6.2 Å as thin black lines; red and blue dots indicate centres of the U3 trimers and midpoints of the shared U⋯U edges of the U4 dihedra, respectively), and the arrangements of the red and blue dots that correspond to the intersection of tetrahedron and octahedron, respectively (d). |