Despite the very important role of atmospheric aerosol nucleation in climate change and air quality, the detailed aerosol nucleation mechanism is still unclear. Here we investigated the formic acid (FA) involved multicomponent nucleation molecular clusters including sulfuric acid (SA), dimethylamine (DMA) and water (W) through quantum chemical method. The thermodynamics and kinetics analysis was based on the global minima given by Basin-Hopping (BH) algorithm coupled with Density Functional Theory (DFT) and subsequent benchmarked calculations. Then the interaction analysis based on ElectroStatic Potential (ESP), Topological and Atomic Charges analysis was made to characterize the binding features of the clusters. The results show that FA binds weakly with the other molecules in the cluster while W binds more weakly. Further kinetic analysis about the time evolution of the clusters show that even though the formic acid weak interaction with other nucleation precursors, its effect on sulfuric acid dimer steady state concentration cannot be neglected due to its high concentration in the atmosphere.

尽管大气气溶胶成核在气候变化和空气质量中起着非常重要的作用，但仍不清楚具体的气溶胶成核机理。在这里，我们通过量子化学方法研究了涉及多组分成核分子簇的甲酸（FA），包括硫酸（SA），二甲胺（DMA）和水（W）。热力学和动力学分析是基于盆地跳跃（BH）算法与密度泛函理论（DFT）以及随后的基准计算得出的全局最小值。然后基于静电势（ESP），拓扑和原子电荷分析进行相互作用分析，以表征簇的结合特征。结果表明，FA与簇中的其他分子弱结合，而W与弱分子结合。