inorganic compounds
Strontium silicon trioxide has been synthesized for the first time and its structure solved. It is isostructural with the germanium analogue SrGeO3 reported by Hilmer [Sov. Phys. Crystallogr. (1963). 7, 573-576], but the true symmetry is monoclinic, rather than hexagonal as reported earlier. The structure has alternate layers of ternary rings of SiO4 groups and close-packed Sr atoms stacked along [001]. Viewed as a polytype, this compound has a six-layer structure and the calcium analogue, -CaSiO3 [Yamanaka & Mori (1981). Acta Cryst. B37, 1010-1017] has a four-layer structure.