THE REFINEMENT OF THE STRUCTURE OF FERROELECTRIC SODIUM-NITRITE

The refinement of the crystal structure of ferroelectric NaNO2 has bee n performed at room temperature by X-ray diffraction. The structure ha s been analyzed by conventional spherical atom and high-order refineme nt methods. Various extinction models have been applied and comparison has been made between the models. The best agreement is obtained for a combination of anisotropic type I and isotropic type II models. X-X( high) maps (2 theta(mi) = 60 degrees) revealed the fundamental feature s of the deformation density.