Succinic acid (SUA) is a common dicarboxylic acid frequently observed in aerosols. Understanding the role of succinic acid in atmospheric new particle formation is essential to study the complicated nucleation mechanism. In this study, high-precision quantum chemical calculations and atmospheric clusters dynamic code (ACDC) simulations are used to investigate the nucleation mechanism of the (SA)_x(SUA)_y(DMA)_z (0 = x, y, z ≤ 3) multicomponent system. The most stable molecular structures show that SUA can form relatively stable clusters with the SA-DMA system by hydrogen bond and proton-transfer interactions. Similar to SA molecules, SUA can provide protons to DMA when excess DMA molecules are available. ACDC simulations indicate that SUA can contribute to the cluster formation, especially at low sulfuric acid concentration and high succinic acid concentration. Moreover, the main cluster flux out of the SUA-containing system is along the non-diagonal (the number of acid molecules is greater than that of base molecules), which is different from the pure SA-DMA system. These clusters are stable enough to be present at a fairly high concentration, and could be a platform for growth into the larger sizes. This organic acid involved cluster formation may explain high nucleation rate at low sulfuric acid concentration and high organic acid concentration.

琥珀酸 (SUA) 是一种常见的二羧酸，经常在气溶胶中观察到。了解琥珀酸在大气新粒子形成中的作用对于研究复杂的成核机制至关重要。在这项研究中，高精度量子化学计算和大气团簇动态代码（ACDC）模拟被用于研究（SA）_x（SUA）_y（DMA）_z的成核机制(0 = x, y, z ≤ 3) 多组分系统。最稳定的分子结构表明，SUA可以通过氢键和质子转移相互作用与SA-DMA系统形成相对稳定的簇。与 SA 分子类似，当有过量的 DMA 分子可用时，SUA 可以为 DMA 提供质子。ACDC 模拟表明 SUA 可以促进簇的形成，尤其是在低硫酸浓度和高琥珀酸浓度下。此外，从含有SUA的系统流出的主要簇流是沿着非对角线（酸分子的数量大于碱分子的数量），这与纯SA-DMA系统不同。这些簇足够稳定，可以以相当高的浓度存在，并且可以成为成长为更大尺寸的平台。