In the FPMD simulations in bulk water and at the air-ice interface, nitrate acid deprotonates within the first picosecond and diffuses away from the nitrate anion via hopping. The solvation environment of NO - 3 equilibrates within the first five picoseconds. The deprotonation of nitric acid in water and on ice by FPMD was reported in detail in previous works and our simulations also saw picosecond time-scale ionization. Additionally, upon deprotonation of the nitric acid we saw efficient proton transfer throughout the solution as well as at the quasi-liquid layer. In the simulations of ammonium nitrate in bulk solution, NH + 4 remains in its ionic form and is sufficiently far from NO - 3 to consider the two ions non-interacting.