1D-O2-1720(1P-30) PDF
Theoretical analysis for stable structures of atmospheric negative ion NO3-(HNO3)2 and its monohydrated cluster
An atmospheric ion NO3-(HNO3)2 serves as nucleus for aerosols. Recently, Sekimoto and Takayama experimentally reported the existence of stable negative ion water clusters, NO3-(HNO3)2(H2O)n, with an atmospheric pressure negative corona discharge mass spectrometry. Geometric structures of these water clusters are, however, still unclear even for monohydrate (n=1). In this study, we theoretically analyzed the negative ion NO3-(HNO3)2 and its monohydrated cluster with first-principle calculations to clarify stable geometries of these ionic clusters. For both systems, we found many isomers being energetically quasi-degenerated to the most stable structure. These results suggest that the various isomers can coexist under a finite temperature condition for both the negative ion and its monohydrate.