Molecular dynamics at water interfaces: from astrophysical to biochemical applications

This PhD thesis investgates the chemical and physical interactions between water and systems of different sizes. The first section illustrates the chemical context of the projects and methodological basis used. The second part studies the dynamics and reactivity of small systems of astrochemical interest on top of water ice, at each step the complexity of the model is increased. Initially the ice surface is characterized, then different aspects of the reaction are examined. The final part explores the interactions between water molecules and two different proteins, to understand water’s role as solvent and how it influences protein macromolecule dynamics. The appendix includes a discussion on the interatomic interaction of water and the contribution apported in CHARMM software package are presented.