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A classical force field for selenium oxyanions in aqueous solutions and minerals
Selenium is one of the health-important natural occurring elements, while its isotope is a major environmental contaminant. Selenium species are highly soluble in water and also occur in mineral structures. In this study, we develop a classical force field for selenate (SeO42−) and selenite (SeO32−) oxyanions. The force field is fitted to the ab initio calculations, including the hydrated properties and equilibrium geometries. It allows to study mobility of selenium ions in aqueous solutions and mineral nanopores using classical molecular dynamics. We calculate structural, transport, and relaxation properties of oxyanions dissolved in aqueous solution. Results show that the number of hydrogen bonds (H-bonds) in the first solvation sphere is higher for SeO32−. Our potential combined with ClayFF force field gives good agreement of minerals structural parameters with ab initio MD calculations.