Nuclear motion of Van der Waals and hydrogen bonded systems

Abstract

Van der Waals and hydrogen bonded systems occur in many areas of chemistry, physics, and biology. A thorough understanding of the nature of these interactions can therefore be of great value. Because of the sometimes great complexity involved, experiments and calculations are done on small model systems which are representative for a particular type of interaction. This type of research is at the most fundamental level of understanding. This thesis is devoted to the quantum chemical investigation of several Van der Waals and hydrogen bonded systems consisting of two diatomic molecules, with a focus on the nuclear motion of these systems. The first system studied is the HF dimer, which is treated in Chapters 2 and 3. Bound states and quasi-bound states are calculated and the infrared photodissociation of this dimer is studied, in particular the vibrational predissociation process. In Chapter 4 attention is shifted to the HCl dimer. In a combined theoretical and experimental study, vibrational predissociation of the HCl-HCl complex is studied. Chapters 5 and 6 deal with the CO dimer. New potential energy surfaces are presented, and calculations of the nuclear dynamics on these surfaces show that they are the first potentials that can qualitatively explain the experimentally observed structure.