Plasma Driven Silver Nanoparticle Growth: Silver nanoparticles have a wide array of applications and are particularly valued for their optical properties. Many of these applications are dependent on specific nanoparticle sizes and shapes, which can be difficult to create consistently and in monodisperse populations. Gaining a fundamental understanding of how silver nanoparticles grow and the factors that influence and drive those growth reactions is the first step in creating design rules for more controlled synthesis. The research that inspired this art aims to understand how silver nanoparticles form, starting from single atoms in solution and progressing through nanoclusters up to the critical nucleation radius. In addition to developing a software, PathTree, to map out and identify the most thermodynamically favorable growth mechanisms, we are also investigating the effects of exposure to a plasma torch on the growth. The reaction sets we have discovered have been applied to kinetics modelling investigating not only the effects of solvated electrons, but also the role of other reducing species that are products of exposing water to plasma. Here we have illustrated some of the early and intermediate optimized nanocluster structures, showing growth from single atoms to small nanoparticles. Contributors: Chelsea M. Mueller, George C. Schatz