First-principles molecular dynamics study on aqueous sulfuric acid solutions.

The properties of aqueous sulfuric acid have been studied employing density functional theory-based molecular dynamics simulations in conjunction with norm-conserving pseudopotentials. The simulations were carried out for two different concentrations whose molar concentrations were fixed at 0.84 and 10.2 mol/l. The structural features of aqueous sulfuric acid solutions show a strong dependency on the concentration. The Grötthuss-type proton transfer mechanism is not effectively operative at the higher concentration because of the broken hydrogen bond network of water induced by ions generated by the dissociation of sulfuric acid. In addition, to evaluate electrical properties, we carried out a simulation that takes an electric field into account. Results are compared with those of the simulation undertaken with no external electric field.