employed. Also, an accurate QC examination of thermodynamic properties necessitates a high level of theory and extra polarized and diffuse basis functions. These methodologies were used for studies of acid-base clusters such as sulfuric acid-ammonia clusters, sulfuric acid-dimethylamine clusters, 62,104 systems involving trimethylamine oxide, 103 sulfuric acid-multi-base clusters, and even multi-acid-multi-base clusters. 105 For these cluster types, the CS procedure via a multi-step funneling approach 6,54 has been well optimized.