Crystallization of metastable monoclinic carnallite, KCl·MgCl2·6H2O: missing structural link in the carnallite family
Paschke, Iris
Schmidt, Horst
Freyer, Daniela
Voigt, Wolfgang
DOI: https://doi.org/10.1107/S2053229620005197
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8932
Pannach, Melanie; Paschke, Iris; Schmidt, Horst; Freyer, Daniela; Voigt, Wolfgang, 2020: Crystallization of metastable monoclinic carnallite, KCl·MgCl2·6H2O: missing structural link in the carnallite family . In: Acta Crystallographica Section C , 76 , 5 , 507 -512, DOI: https://doi.org/10.1107/S2053229620005197.
Abstract
During evaporation of natural and synthetic K–Mg–Cl brines, the formation of almost square plate-like crystals of potassium carnallite (potassium chloride magnesium dichloride hexahydrate) was observed. A single-crystal structure analysis revealed a monoclinic cell [a = 9.251 (2), b = 9.516 (2), c = 13.217 (4) Å, β = 90.06 (2)° and space group C2/c]. The structure is isomorphous with other carnallite-type compounds, such as NH4Cl·MgCl2·6H2O. Until now, natural and synthetic carnallite, KCl·MgCl2·6H2O, was only known in its orthorhombic form [a = 16.0780 (3), b = 22.3850 (5), c = 9.5422 (2) Å and space group Pnna].