The movie on the top shows a molecular dynamics simulation of dilute H3O+ ions in bulk water at 1 atm and 300 K with a non-reactive potential that allows strictly for vehicular diffusion. The movie on the bottom shows a molecular dynamics simulation of dilute H3O+ ions in bulk water at 1 atm and 300 K with a reactive potential that allows for both vehicular and structural diffusion. The motion of the hydroniums is much greater when structural diffusion is incorporated. White = H Red = O in water molecule Green = O in Hydronium Ion