Hydration structure of Y and La compared; An Application of metadynamics

Ikeda, Takashi; Hirata, Masaru ; Kimura, Takaumi 

We studied the hydration structures of Y and La 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 chloro-aqua complexes are successfully generated within the time scales 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.