A Theoretical Model to Calculate Fundamental Physical Parameters for Molecule–Particle Interactions

Abstract

Publisher Summary The interaction between a molecule or atom and a liquid or solid aerosol particle (AP) can be treated almost similar to the interaction between an N-atomic molecule (NAM) and a surface. Therefore a NAM–AP interaction can be divided into the elementary steps: (1) diffusion of the molecule to the AP, (2) adsorption of the molecule at the AP, (3) chemical reaction on the AP, (4) desorption of products from the AP, and (5) diffusion of products away from the AP. This chapter discusses the first results of a new Quantum-statistical (QM-ST) model that can be used to calculate total sticking coefficients for molecules/atoms impinging on an aerosol/surface. The advantage of the model is that very limited numbers of parameters are needed to calculate the accommodation coefficient. All the parameters like spectroscopic data for the molecule impinging on the aerosol and the potential energy difference between the reaction and product channels can, with good accuracy, be calculated using electronic structure theory. However, if it is possible to use full reaction dynamics to calculate the sticking coefficient for a molecular/aerosol system, then this method will be preferable. Unfortunately, reaction dynamics need full potential energy information and this is only known for very few NAM–AP systems.