Redetermination of β-Ba(PO3)2

Abstract

In comparison with the previous structure determination of the β-modification of bariumcatena-polyphosphate that was based on Weissenberg film data [Grenieret al.(1967).Bull. Soc. Fr. Minéral. Cristallogr.90, 24–31], the current CCD-data-based redetermination reveals all atoms with anisotropic displacement parameters, standard uncertainties for the atomic coordinates, and the determination of the absolute structure. Moreover, a much higher accuracy in terms of the bond-length distribution for the polyphosphate chain, with two shorter and two longer P—O distances, was achieved. The structure consists of polyphosphate chains extending parallel to [100] with a periodicity of two PO4tetrahedra. The Ba2+cations are located between the chains and are surrounded by ten O atoms in the form of a distorted coordination polyhedron, with Ba—O distances ranging from 2.765 (3) to 3.143 (3) Å, also reflecting the higher precision of the current redetermination.