Effect of Mg^2+ on the structure of amorphous CaCO3 -- A molecular dynamics simulation
Abstract
Molecular dynamics (MD) simulations of amorphous calcium carbonate (ACC) were carried out to investigate the effect of Mg^2+ ions on the structure of CaCO3 crystal nucleus formed from ACC@. Our systems contained 432 CaCO3 with several concentrations of MgCO3. In this study, our original ion model of Mg^2+ was developed and combined with Raiteri model of Ca^2+ and rigid CO3^2- [1]. The simulations indicated that the fraction of vaterite-like ion arrangement was much larger than those of calcite-like and aragonite-like ion arrangements in pure ACC@. However, as the Mg^2+ concentration increased, the faction of vaterite-like ion arrangements decreased, which suggests that Mg^2+ ions play as inhibitors of vaterite nucleation. The result explains why calcite or aragonite is preferentially nucleated in the presence of Mg^2+, whereas vaterite is nucleated in the absence of them.[1] P. Raiteri, J. D. Gale, D. Quigley, and P. M. Rodger, J. Phys. Chem. C 114, 5997 (2010).
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- February 2012
- Bibcode:
- 2012APS..MARV32014T