Cover illustration: The molecular structure of nonactin, with displacement ellipsoids shown at the 80% probability level and all H atoms omitted. See Guzei, Wang, Zhan, Dolomanov & Cheng [Acta Cryst. (2009), C65, o512-o514].
The structure of Bi4Ge3O12 (I3d, Z = 4) was investigated at 7.30 GPa, close to the onset of amorphization, using single-crystal X-ray diffraction in a diamond anvil cell at room temperature. No pressure-induced phase transition was observed up to this pressure.
The title compound, europium(II) iodide, is a new low-temperature phase crystallizing in the space group Pnma. Density-functional calculations on the various EuI2 phases and temperature-dependent X-ray analysis corroborate each other. All phases are built up by EuI7 polyhedra, but they differ in their packings.
Rietveld refinement of the novel vanadium aliovalent substituted zirconium tungstate ZrW1.8V0.2O7.9, using combined X-ray and neutron diffraction data, shows that its average structure is similar to that of β-ZrW2O8, with substitution occurring only at one of the W sites.