We model with molecular resolution structure and chemical dynamics of finite pieces of matter (clusters, nanodroplets, systems with extended surfaces, solvated biomolecules, etc.). In particular, we put a lot of effort into unraveling fundamental aspects of ion solvation in anisotropic and inhomogeneous environments. These range from the surfaces of aqueous droplets to solution/protein interfaces. Using molecular dynamics simulations and quantum chemical methods we are trying to figure out what drives ions to these interfaces and to one another. These specific ion effects have been observed since late 1800s, but only now it is becoming feasible to investigate the molecular mechanisms involved with atomic detail. Not only are we thrilled by the basic science we are discovering but also by applications our results are finding, which range from the chemistry of atmospheric aerosols to controlling enzymatic activity. Our related research activities concern modeling of ice nucleation, relevant for atmospheric chemistry and physics, and electron solvation, pertinent to radiation chemistry and DNA damage.