α-Lead tellurite from single-crystal data

• Main Authors: Adam I. Stash, Sergey A. Ivanov, Valery E. Zavodnik
• Format: Article
• Language: English
• Published: International Union of Crystallography 2008-03-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536808003267

The crystal structure of the title compound, α-PbTeO3 (PTO), has been reported previously by Mariolacos [Anz. Oesterr. Akad. Wiss. Math. Naturwiss. Kl. (1969), 106, 128–130], refined on powder data. The current determination at room temperature from data obtained from single crystals grown by the Czochralski method shows a significant improvement in the precision of the geometric parameters when all atoms have been refined anisotropically. The selection of a centrosymmetric (C2/c) structure model was confirmed by the second harmonic generation test. The asymmetric unit contains three formula units. The structure of PTO is built up of three types of distorted [PbOx] polyhedra (x = 7 and 9) which share their O atoms with TeO3 pyramidal units. These main anionic polyhedra are responsible for establishing the two types of tunnel required for the stereochemical activity of the lone pairs of the Pb2+ and Te4+ cations.