New particle formation (NPF) is responsible for the birth of approximately 50% of aerosol particles formed in the atmosphere, and results from the clustering of low volatility gaseous vapors. Acid-base chemistry and salt bridge formation play an important role in stabilizing early stage NPF clusters against evaporation, allowing these clusters to grow into atmospherically relevant sizes. Sulfuric acid -ammonia (-water) clusters have previously been studied in depth as these particles make up a majority of post-industrial revolution NPF contributors. However, in mid-latitude coastal and polar regional NPF events, H 2 SO 4 -NH 3 (-H 2 O) cluster formation rates alone could not account for observed NPF rates. Further investigation into these regional events led to the discovery that the presence of iodine in these regions helps fuel these NPF events. Coastal algae and other biota release I 2 , 23-26 HOI, and various organo-iodide species, such as CH 2 I 2 , at low tide, which can form various iodine oxoacids and iodine oxides through photolysis and photooxidation. Coastal nutrient enhancement, likely due to runoff, has greatly increased the algae population along with other anthropogenic emissions on and near the coast of China and has resulted in regionally high iodine concentrations. Since pre-industrial times, it's believed that there has been a 70% increase in atmospheric iodine. I -in sea water in the presence of ample ozone concentrations, can also lead to the formation and emission of various organo-iodide compounds into the atmosphere. During the day, if concentrations of CH 2 I 2 are in the 10s of ppt range, NPF can take place without any other contributing species. It has even been found that iodine oxoacid nucleation rates are higher than those of sulfuric acid -ammonia clusters at equal concentrations of acids. In the Arctic, over pack ice, the concentration of iodic acid is 6 -10 times higher than that of sulfuric acid, and as a result NPF events are primarily centered around HIO 3 , with minimal to no participation from sulfuric acid or any other species. Since acid-base chemistry plays such an important role in these early stage NPF clusters, the role of ammonia has also been explored in iodine containing clusters as it is important in stabilizing sulfuric acid and nitric acid containing clusters. It was found that ammonia can aid in the hydrolysis of I 2 O 5 and it can also interact with HIO 3 , increasing nucleation rates of these clusters through the lowering of transition state energies via increased hydrogen bond donors and acid-base interactions. Further quantum chemical calculations and atmospheric cluster dynamics code (ACDC) simulations probing the role of sulfuric acid and ammonia on iodic acid nucleation rates also found that ammonia can help stabilize these clusters and enhance growth rates. There has been some debate on whether or not I 2 O 5 and other iodine oxides are the driving force behind the formation of these clusters or whether HIO 3 and iodine oxoacids play a more substantial role. Iodic acid dimers can directly form I 2 O 5 via a single dehydration reaction even though it has typically been believed to be a multiple step process. Nevertheless, exploration into the dehydration of iodic acid into iodine pentoxide has been found to be somewhat unfavorable based off of quantum chemical calculations, as it takes an energy input to proceed through the proposed transition states. Studies on the hydrolysis of iodine oxides and atomic iodine to form HIO 3 determined that water actually reacts quite slowly with these components, suggesting that clustering of iodine oxides is the primary channel of this type of cluster formation. Yet, specific relative humidity ranges of less than 65% have been found to promote this hydrolysis reaction of I 2 O 5 to HIO 3 , which is an atmospherically plausible range. The importance of iodine oxides beyond cluster conception has been a source of controversy as well. IO 2 , for example, has been found to play a more crucial role in the early growth stages of particle formation compared to initial cluster formation. However, in the Arctic Ocean, its been found that iodic acid almost exclusively propels NPF events. Other studies in Greenland; Maud Land, Antarctica; and Mace Head, Ireland, have also identified high concentrations of atmospheric iodic acid and concluded that clustering of HIO 3 is the dominant formation pathway, with the formation of I 2 O 5 resulting from internal cluster rearrangement. Various field studies, quantum chemical simulations, and laboratory experiments have been utilized to study these iodine containing atmospheric particles. Mass spectrometric and CLOUD studies have been conducted on anionic and cationic iodine oxide and iodine oxoacid clusters. However, no experiments have been performed on these clusters in order to glean structural information to help assist climate modelling for this subset of clusters 54 even though ionic iodic acid nucleation has yet to be incorporated into these global climate models.