  We present a new approach to studying nanoparticle collisions using Density
Functional based Tight Binding (DFTB). A novel DFTB parameterisation has been
developed to study the collision process of Sn and Si nanoparticles (NPs) using
Molecular Dynamics (MD). While bulk structures were used as training sets, we
show that our model is able to accurately reproduce the cohesive energy of the
nanoparticles using Density Functional Theory (DFT) as a reference. A
surprising variety of phenomena are revealed for the Si/Sn nanoparticle
collisions, depending on the size and velocity of the collision: from
core-shell structure formation to bounce-off phenomena.
