By comparing to the RDF of HNO 3 on ice, we see that when an ion complex is formed, in both cases, the solvation shell of NO - 3 on ice is partly disrupted. This leads to a lower first peak of the O n -H w and O n -O w RDFs, similar to that obtained for nitrate in bulk water at 300 K, while the structure of the RDF beyond the first solvation peak changes as a function of the presence and the protonation state of ammonium/ammonia. From these RDFs, we learn that in terms of solvation environment, there are slight differences between water and ice due to the more ordered structure of the quasi-liquid layer. However, if a counter ion is close enough to disrupt the first solvation shell then this leads to significant differences in the water structuring around the ion, which we will see below.