6-Fold-Coordinated Beryllium in Calcite-Type Be[CO<sub>3</sub>]
Dominik Spahr, Lkhamsuren Bayarjargal, Е. Быкова, Maxim Bykov, Lukas Brüning, Valentin Kovalev, Victor Milman, Jonathan P. Wright, Björn Winkler
Abstract
The anhydrous beryllium carbonate Be[CO 3 ] with calcite-type crystal structure was obtained by a reaction of BeO with CO 2 in a laser-heated diamond anvil cell at pressures between 30 GPa and 80 GPa and elevated temperatures. Its calcite-type crystal structure ( R 3̅ c with Z = 6) is characterized by 6-fold-coordinated beryllium atoms forming [BeO 6 ] octahedra and by trigonal-planar [CO 3 ] 2– groups. The crystal structure was determined by synchrotron-based single-crystal X-ray diffraction and confirmed by density-functional-theory-based calculations in combination with experimental Raman spectroscopy. Calcite-type Be[CO 3 ] was synthesized at significantly lower pressures than the other very few compounds hosting 6-fold-coordinated beryllium, and it is the first beryllium carbonate with this coordination.