In our previous studies on large (SA) n (AM) n clusters, we exclusively used ionic monomers in the ABCluster configurational sampling (CS), as proton transfer occurs in all SA-base clusters larger than 2 acid-base pairs. To verify that this is a reasonable assumption, we performed CS (lm=2000, gen=1000, sc=4, pop=300) for all 216 possible combinations of the acid monomeric unit (trans-H 2 SO 4 , cis-H 2 SO 4 , HSO - 4 , and SO 2- 4 ) and the base monomer unit (NH 3 and NH + 4 ) which lead to the overall-neutral (SA) 10 (AM) 10 cluster.