Compressional behavior of the aragonite‑structure carbonates to 6 GPa
Metadatos
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Springer Nature
Materia
Orthorhombic carbonates Aragonite group Compressibility Density functional theory Quantum theory of atoms in molecules
Date
2023-04-05Referencia bibliográfica
Vidal-Daza, I., Sánchez-Navas, A. & Hernández-Laguna, A. Compressional behavior of the aragonite-structure carbonates to 6 GPa. Phys Chem Minerals 50, 13 (2023). [https://doi.org/10.1007/s00269-023-01237-6]
Patrocinador
Spanish Government; European FEDER Grants FIS2016-77692-C2.2PCIN-2017-098; Junta de Andalucia RNM-264-363 RNM-264-1897 PAIRésumé
The behaviors of aragonite (CaCO3 ), strontianite (SrCO3 ), cerussite (PbCO3 ), and witherite (BaCO3 ) at increasing pressure
have been studied up to 6 GPa using density functional theory with plane waves. A parallelism of the orthorhombic
carbonates with the closed-packed AsNi structure is considered in our analysis, being the CO2−
3 groups not centered in the
interstice of the octahedron. The decomposition of the unit-cell volume into atomic contributions using the Quantum Theory
of Atoms in Molecules has allowed the analysis of the bulk modulus in atomic contributions. The bulk, axes, interatomic
distances, and atomic compressibilities are calculated. The largest compression is on the c crystallographic axis, and the c
linear modulus has a linear function with the mineral bulk modulus ( K
0 ). Many of the interatomic distances moduli of the
alkaline earth (AE) carbonates show linear functions with the bulk modulus; however, the whole series (including cerussite)
only gives linear functions when K
0 is related either with the CC distances modulus or the modulus of the distances of
the C to the faces of the octahedron perpendicular to c. These last distances are the projections of the Metal–Oxygen (MO)
distances to the center of the octahedron. K
0AE carbonates also show linear functions with the atomic moduli of their cations.
However, the whole series show a linear relation with the atomic modulus of C atoms. Therefore, the whole series highlight
the importance of the C atoms and their interactions in the mechanism of compression of the orthorhombic carbonate series.