Evidence in support of levitation effect as the reason for size dependence of ionic conductivity in water: a molecular dynamics simulation.

摘要: We report extensive molecular dynamics simulations of (i) model ions in water at high concentrations as a function the size and charge ion well (ii) realistic simulation Cl- Br- low room temperature. also analyze existing experimental data light results obtained here. The halide have been carried out using interaction potentials Koneshan et al. (J. Phys. Chem. B 1998, 102, 4193). compute structural dynamical properties explore their variation with ion. find that certain intermediate sizes exhibit maximum self-diffusivity agreement previous measurements computer simulations. trajectories understanding levitation effect (LE) recent suggestion ionic conductivity has its origin LE 2005, 109, 8120). distribution void neck radii exist amidst water. Our analysis suggests is characterized by lower activation energy single-exponential decay F(s)(k,t). behavior these other related quantities are characteristic anomalous regime LE. yield predictions A plot literature for alkali Kay Evans 1966, 70, 2325) yields excellent To best our knowledge, none theories predict conductivity.