Understanding carbonate mineral crystallisation from atomistic simulations of ion association and surface adsorption processes

Carbonate minerals are widespread and found both in geological settings and in living organisms as a result of biomineralisation. As major carbon reservoirs, they play a key role in the global carbon cycle and are at the heart of technological challenges such as long-term CO₂ sequestration. Despite their ecological and economic relevance, the nucleation and growth mechanisms of these compounds as well as their structure and relative stability are still under investigation.

This talk will illustrate how molecular dynamics and free energy methods can probe water exchange and ion association events in solution [1], as well as the adsorption of constituents and small organics on mineral surfaces at the interface with aqueous solution [2], in the context of understanding carbonate mineral crystallisation. A structural and thermodynamic study of metastable hydrated carbonates combining first-principles and classical theoretical methods will also be presented [3]. Despite the huge increase in computer resources over the past decades and rise of GPU technology, compromise is still required between computational cost, system sizes and timescales of processes, with different questionings calling for different levels of theory. Therefore, the strengths and limitations of using first-principles methods and different types of force fields, based on rigid-ion or polarizable models, will be highlighted.

[1] Aufort et al. Earth Space Chem., 2022, 6, 733

[2] Aufort et al. Cryst. Growth Des., 2022, 22, 1445

[3] Aufort & Demichelis, Cryst. Growth Des., 2020, 20, 8028