{"DOI":"10.1515/znb-1996-0807","abstract":"Single crystals of Sr2(VO)2Si4O12 could be obtained by high-pressure high-temperature reaction of a SrSiO3/SiO2/V2O5 mixture in a modified Belt-type apparatus. The green crystals are orthorhombic, space group Cmcm, with a = 5.3139(3), b = 14.6281(7), c = 7.0329(4) \u00c5 and Z = 2. The structure comprises vierer single chains of SiO4 tetrahedra, the resulting Si4O12 units being connected by VO5 square pyramids. There is one short distance (V - O = 1.61 (1) \u00c5) within the square pyramid, giving definite evidence to a (VO)2+ group with a V = O double bond.\n\t\t\t\tThe crystal structure of microcrystalline Sr2(TiO)2Si4O12, obtained by high-pressure hightemperature reaction of a SrSiO3/SiO2/TiO2 mixture, was refined by the Rietveld technique. The compound (Cmcm, a = 5.3530(2), b = 14.4864(7), c = 7.0817(3) \u00c5, Z = 2) is isostructural with the vanadium compound.","author":[{"family":"Berger"},{"family":"Range"}],"id":"unknown","issued":{"date-parts":[[1996,8,1]]},"page-first":"1099","publisher":"Walter de Gruyter GmbH","title":"Zwei Metasilicate mit Vierer-Einfach-Ketten: Hochdrucksynthese und Strukturverfeinerung von Sr2(VO)2Si4O12 (Haradait) und Sr2(TiO)2Si4O12 / Two Metasilicates with Vierer Single Chains: High-Pressure Synthesis and Structure Refinement of Sr2(VO)2Si4O12 (Haradaite) and Sr2(TiO )2Si4O12","type":"article-journal","volume":"51"}