Calcium chlorite, Ca(ClO2)2, from X-ray powder diffraction data

Abstract

The structure of calcium chlorite, Ca(ClO2)2, has been refined from X-ray powder diffraction data using the Rietveld method. The compound crystallizes in the ortho­rhom­bic space group Ccca (Ccce), with Z = 4. The structure is based on separate layers parallel to the ac plane, consisting of calcium cations that are coordinated by chlorite anions; the O atoms form almost ideal square antiprisms. Within the layers, each anion bridges four metal cations. The Ca atoms are located on special positions of 222 symmetry, the Cl atoms lie on twofold axes and the O atoms are in general positions. The compound is isostructural with strontium chlorite, Sr(ClO2)2, and lead chlorite, Pb(ClO2)2.