The division performs fundamental experimental and theoretical research on inherent properties of atomic systems and on atomic collision processes in the broad sense. The experiments are mostly carried out at the DESIREE facility at the Department of Physics, a very powerful facility for different types of experiments with ions from atoms, molecules and clusters at low temperatures. We also study antihydrogen and interactions between atoms and electromagnetic radiation on extremely short time scales (attoseconds). Our activities are connected to nearby fields of research, in particular to astrophysics but also to atmospheric sciences and biophysics on a molecular level.