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  • Simulation of association in water: From ion pairing to crystal growth

    Speaker: Professor Julian Gale
    Institute: Curtin University
    Country: Australia
    Speaker Link: https://research.curtin.edu.au/supervisor/prof-julian-gale/

    Professor Julian Gale

    Curtin Institute for Computation/School of Molecular and Life Sciences, Curtin University, PO Box U1987, Perth, WA 6845, Australia

    Many fundamental processes in nature are driven by association of dissolved species in the presence of a solvent, which is typically water. One particularly significant example is biomineralization which is responsible for forming everything from bones and teeth, through to underpinning creation of coral reefs and carbon sequestration. Here dissolved metals ions such as Ca2+ combine with anions such as carbonate and phosphate to ultimate form minerals via a series of complex steps that are still hotly debated [1,2].

    Computational chemistry is able to contribute to our understanding of aqueous binding and crystallization through the potential to quantify the thermodynamics of ion association processes in water, from the initial ion pairing [3] through the surface adsorption of ions that leads to crystal growth [4]. This presentation will focus on some of the computational challenges and pitfalls relating to the quantitative determination of free energies for these association processes in water from molecular dynamics simulation. In particular, the question of how to obtain an accurate potential energy surface will be examined [5], as well as the problem of determining the free energy landscape for complex environments in order to determine meaningful equilibrium constants.

    Recording:

    Video is available only for registered users.

    References

    [1] J.J. De Yoreo et al, Science, 349, 498 (2015)

    [2] D. Gebauer et al, Am. J. Sci., 318, 969 (2018)

    [3] P. Raiteri, R. Demichelis and J.D. Gale, J. Phys. Chem. C, 119, 24447 (2015)

    [4] M. De La Pierre et al, Angewandte Chemie, 56, 8464 (2017)

    [5] P. Raiteri, A. Schuitemaker and J.D. Gale, J. Phys. Chem. B, 124, 3568 (2020)