The cloud chamber has long been a paragon of experimental physics,but its classical design makes it difficult to measure its physical parameters while in use. Additionally, recent research in cloud chamber physics indicates that the walls of the chamber play a larger role than previously imagined. We therefore develop a computer simulation of a cloud chamber, so that we can study cloud chamber mechanics without the limitations of real-world experiments. This simulation attempts to accurately model an ideal wall-less diffusion cloud chamber at the molecular level, and is hoped to be extended to a walled chamber to model wall effects.