Ab initio simulations of sulfuric acid solutions

Ab initio molecular dynamics simulations are presented for a solution consisting of a single H₂SO₄ molecule in a periodic box with 63 water molecules. Three trajectories lasting 35–55 ps were calculated at temperatures in the 320–326 K range, for two functionals, and double- and triple-zeta quality basis sets. All three trajectories displayed prompt ionization of the first proton. The ion displayed varying extents of ionization in the different trajectories. Proton hopping was observed between the oxygen atoms. Moreover, hopping of the solvating water molecules also occurred between the different oxygen atoms of the anions, with bidentate water, hydrogen bonding to two different oxygen atoms, serving as an intermediate.