Compressional behavior of the aragonite-structure carbonates to 6 GPa Vidal-Daza, Isaac Sánchez Navas, Antonio Hernández Laguna, Alfonso Orthorhombic carbonates Aragonite group Compressibility Density functional theory Quantum theory of atoms in molecules Supplementary Information The online version contains supplemen- tary material available at https://doi.org/10.1007/s00269-023-01237-6. 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 (K0 ). 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 K0 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. K0AE 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. 2023-05-17T08:59:00Z 2023-05-17T08:59:00Z 2023-04-05 journal article 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://hdl.handle.net/10481/81609 10.1007/s00269-023-01237-6 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Springer Nature