Theoretical Study of Water Affinity of Atmospheric (H2SO4)₃-(NH3)₃ Cluster

Aerosols have a great impact on global climate, air quality and human health. New particle formation (NPF) is a major source of atmospheric aerosols. Overall, NPF is mainly divided into three stages: the generation stage, nucleation stage and growth stage. In recent years, scientists have used field observations and smoke box simulation experiments to study new particle generation events around the world. However, restricted by experimental observations and characterization methods, the microscopic mechanism of the formation of new particles is still unclear. Quantum chemical calculations have obvious advantages in exploring chemical reaction mechanisms. Studying the nucleation mechanism of sulfuric acid-ammonia-water clusters in the atmosphere at the molecular level can provide valuable information for understanding the growth mechanism of water molecules on acid-base clusters and environmental management. In this work, we use quantum chemical calculation methods to study the mechanism of forming stable clusters in water molecules using small molecules of ammonia and sulfuric acid and explain how the sulfuric acid-ammonia cluster changes as the water molecules is increased.