The partmc model is developed to simulate the evolution of aerosol particles in the atmosphere. Atmospheric aerosol particles are usually composed of complex mixtures of different chemical species, ranging in size from a few nanometers to tens of microns. Partmc model is very suitable for particle analysis because it can solve the whole synthesis space explicitly without any prior assumption of particle composition. Since the composition of each particle determines the optical properties of aerosols and the ability to form cloud droplets, these details are very important for determining the impact of aerosols on climate.