The crystal structure of bicchulite, Ca2[Al2SiO6](OH)2

Abstract

Abstract The crystal structure of synthetic bicchulite was determined with single-crystal x-ray methods (R = 0.07 for all 65 observed reflections). Bicchulite has a sodalite-type framework structure with Al and Si distributed statistically in the tetrahedral sites, coordinated solely by oxygen atoms. Calcium is coordinated octahedrally by three oxygen atoms and three OH groups. Four such octahedra are linked to a group by OH–OH edges. These octahedra groups occupy the cavities within the framework.