Synthesis of calcium orthocarbonate, Ca2CO4-Pnma at PT conditions of Earth's transition zone and lower mantle

J Binck, D Laniel, L Bayarjargal… - American …, 2022 - degruyter.com
We show, by single-crystal diffraction studies in laser-heated diamond-anvil cells, that
Ca2CO4 orthocarbonate, which contains CO44− tetrahedra, can be formed already at~ 20 …

[HTML][HTML] Structure and elasticity of CaC2O5 suggests carbonate contribution to the seismic anomalies of Earth's mantle

H Wang, L Liu, Z Gao, L Yang, G Naren… - Nature …, 2024 - nature.com
Abstract Knowledge of carbonate compounds under high pressure inside Earth is key to
understanding the internal structure of the Earth, the deep carbon cycle and major …

Tetrahedrally Coordinated sp3-Hybridized Carbon in Sr2CO4 Orthocarbonate at Ambient Conditions

D Spahr, J Binck, L Bayarjargal, R Luchitskaia… - Inorganic …, 2021 - ACS Publications
We have synthesized the orthocarbonate Sr2CO4, in which carbon is tetrahedrally
coordinated by four oxygen atoms, at moderately high pressures [20 (1) GPa] and high …

Sr3[CO4]O Antiperovskite with Tetrahedrally Coordinated sp3-Hybridized Carbon and OSr6 Octahedra

D Spahr, J König, L Bayarjargal… - Inorganic …, 2021 - ACS Publications
We have synthesized the orthocarbonate Sr3 [CO4] O in a laser-heated diamond anvil cell at
20 and 30 GPa by heating to≈ 3000 (300) K. Afterward, we recovered the orthocarbonate …

Orthocarbonates of Ca, Sr, and Ba—The Appearance of sp3-Hybridized Carbon at a Low Pressure of 5 GPa and Dynamic Stability at Ambient Pressure

PN Gavryushkin, DN Sagatova, N Sagatov… - ACS Earth and Space …, 2021 - ACS Publications
Orthocarbonates are a newly discovered class of compounds that are stable at high
pressures. The presence of sp3-hybridized carbon, having structural similarity to …

Crystal structures and P–T phase diagrams of SrCO and BaCO

DN Sagatova, PN Gavryushkin… - Journal of …, 2023 - Wiley Online Library
In this study, we present the results of a search for new stable structures of SrC 2 O 5 and
BaC 2 O 5 in the pressure range of 0–100 GPa based on the density functional theory and …

High-pressure transformations of CaC 2 O 5–a full structural trend from double [CO 3] triangles through the isolated group of [CO 4] tetrahedra to framework and …

DN Sagatova, PN Gavryushkin, NE Sagatov… - Physical Chemistry …, 2022 - pubs.rsc.org
Over the past few years, the concept of carbonates, as the salts of MCO3 or composition with
[CO3] triangles in the crystal structures, was sufficiently extended. In addition to carbonates …

Phase stabilities of and -II studied by Raman spectroscopy, x-ray diffraction, and density functional theory calculations

J Binck, L Bayarjargal, SS Lobanov, W Morgenroth… - Physical Review …, 2020 - APS
Carbonates are the major hosts of carbon on Earth's surface and their fate during subduction
needs to be known to understand the deep carbon cycle. Magnesite (MgCO 3) is thought to …

Calcium orthocarbonate, Ca2CO4-Pnma: A potential host for subducting carbon in the transition zone and lower mantle

D Sagatova, A Shatskiy, N Sagatov, PN Gavryushkin… - Lithos, 2020 - Elsevier
A novel structure of calcium orthocarbonate Ca 2 CO 4-Pnma has been discovered using ab-
initio crystal structure prediction methods (AIRSS and USPEX) based on the density …

First Finding of High-Pressure Modifications of Na2CO3 and K2CO3 with sp3-Hybridized Carbon Atoms

PN Gavryushkin, NE Sagatov, DN Sagatova… - Crystal Growth & …, 2023 - ACS Publications
The transition from structures with classical [CO3] triangles to structures with [CO4]
tetrahedra, corresponding to the transition from sp2 to sp3 hybridization of carbon atoms, is …