The hydrocarbon-bearing clathrasil chibaite and its host-guest structure at low temperature.

ABSTRACT: The natural sII-type clathrasil chibaite [chemical formula SiO₂·(M¹²,M¹⁶), where M^x denotes a guest mol-ecule] was investigated using single-crystal X-ray diffraction and Raman spectroscopy in the temperature range from 273 to 83 K. The O atoms of the structure at room temperature, which globally conforms to space group [V = 7348.9 (17) ų, a = 19.4420 (15) Å], have anomalous anisotropic displacement parameters indicating a static or dynamic disorder. With decreasing temperature, the crystal structure shows a continuous symmetry-lowering transformation accompanied by twinning. The intensities of weak superstructure reflections increase as temperature decreases. A monoclinic twinned superstructu

SUBMITTER: Scheidl KS 

PROVIDER: S-EPMC6126654 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature