Crystal structure of NaHfSiO by Rietveld refinement.

The structure of triclinic disodium hafnium disilicate, NaHfSiO, has been determined by laboratory powder X-ray diffraction and refined by the Rietveld refinement. The structure is a framework made of alternate layers of HfO octa-hedra and SiO tetra-hedra linked by common O atoms. Sodium atoms are located in the voids of the framework, aligned into tunnels along the [010] direction. NaHfSiO is isostructural with the parakeldyshite NaZrSiO phase.