DOI: 10.1021/cg100055p
Published as part of a virtual special issue of selected papers presented in celebration of the 40th Anniversary Conference of the British Association for Crystal Growth (BACG), which was held at Wills Hall, Bristol, UK, September 6-8, 2009
2010, Vol. 10 4292–4302
First Principles Simulations of the Structural and Dynamical Properties of Hydrated Metal Ions Me2þ and Solvated Metal Carbonates (Me=Ca, Mg, and Sr) Devis Di Tommaso* and Nora H. de Leeuw Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom Received January 15, 2010; Revised Manuscript Received August 5, 2010
ABSTRACT: The structural and dynamical properties of the alkaline earth metal ions Mg2þ, Ca2þ, and Sr2þ and their carbonate and bicarbonate complexes in aqueous solution are examined through first principles molecular dynamics simulations based on the density functional theory. Calculations were conducted in explicit heavy water molecules and at the average temperature of 400 K, conditions which are necessary to obtain a liquid-like water structure and diffusion time-scales when using gradient corrected density functionals. According to these simulations, the magnesium ion undergoes a significant contraction of its coordination sphere in the Mg(H)CO3(þ) aqueous complex, whereas calcium and strontium increase their average first shell coordination number when coordinated to HCO3- or CO32-. The analysis of the water exchange processes in the hydration shells of the metals suggests the following order for metal reactivity in solution: Mg2þ
