Hydration structure of Y3+ and La3+ compared:: An application of metadynamics -: art. no. 244507

We studied the hydration structures of Y3+ and La3+ in aqueous solutions by applying the metadynamics method recently introduced as a tool to explore reaction pathways based on the Car-Parrinello molecular dynamics. By employing the metal-water oxygen coordination number as a collective variable of the metadynamics a couple of aqua and chloroaqua complexes are successfully generated within the time scale of 10 ps. The reconstructed free-energy surface captures the characteristics of the hydration of the light and heavy trivalent rare-earth ions. The present study demonstrates that the metadynamics based on the Car-Parrinello molecular dynamics is a promising tool for exploring the free-energy surface of complicated systems such as solutions. (c) 2005 American Institute of Physics.