ChemInform Abstract: Revisiting the Crystal Structure of Rhombohedral Lead Metaniobate.

Abstract

Revisiting the Crystal Structure of Rhombohedral Lead Metaniobate. -The crystal structure of rhombohedral PbNb 2O6 is re-examined by powder XRD and powder neutron diffraction in combination with ab initio DFT calculations. The rhombohedral polymorph crystallizes in the space group R3, in contradiction to the previously reported space group R3m. The crystal structure consists of edge-sharing dimers of NbO 6 octahedra forming layers with 6-and 3-fold rings of octahedra. The lead ions are placed in channels formed by these rings. The layers are connected by corner-sharing octahedra. -(OLSEN, G. H.; SOERBY, M. H.; HAUBACK, B. C.; SELBACH, S. M.; GRANDE*, T.; Inorg. Chem. 53 (2014) 18, 9715-9721, http://dx.doi.org/10.1021/ic5012378 ; Norw. Univ. Sci. Technol., N-7491 Trondheim, Norway; Eng.) -W. Pewestorf 45-002