Disordered rhombohedral K2Ca2(CO3)3: a supposedly transient state within an ambiguous transformation route on decompression

Author(s): Ronald Miletich, S. Miloš, P. Lotti, A. Likhacheva, A. Romanenko, S. Rashchenko, A. Shatskiy
Abstract: Within the K₂CO₃-CaCO₃ system on P,T variation relevant to the Earth's geotherm [1], trigonal K₂Ca₂(CO₃)₃ is one of the known solid key phases with an apparent stability under the conditions of formation. Early descriptions report on intensive polysynthetic twinning in morphologically trigonal crystals [2], and the structure was later solved according to acentric R3 space-group symmetry, but with a model proposed by Winbo et al. (1997) [3] showing conspicuous ADP's and bond lengths.
Organisation(s): Department of Mineralogy and Crystallography
External organisation(s): Università degli Studi di Milano, Siberian Branch of the Russian Academy of Sciences, Russian Academy of Sciences
Journal: Acta Crystallographica. Section A: Foundation and Advances
Volume: 2024
No. of pages: 1
ISSN: 0108-7673
DOI: https://doi.org/10.1107/s205327332409750x
Publication date: 08-2024
Peer reviewed: Yes
Austrian Fields of Science 2012: 105113 Crystallography, 105116 Mineralogy
Portal url: https://ucrisportal.univie.ac.at/en/publications/3bf125ea-c4dd-46f8-a15c-ffbc0a9e1be2

Disordered rhombohedral K<sub>2</sub>Ca<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>: a supposedly transient state within an ambiguous transformation route on decompression