Intermolecular interactions shape the world around us, enabling the existence of life as we know it on this planet. They are involved in numerous physico-chemical and biological processes: from condensation of liquids to protein-ligand interaction. Certainly, life makes extensive use of these interactions. Therefore, a deep knowledge of the intermolecular interactions is required in order to understand all those processes, including the biochemistry of life. However, due to their small module, characterization of non-covalent interactions is by no means an easy task. Here we will present an example of how by combining laser and microwave spectroscopy in molecular beams, it is possible to form molecular aggregates and solve their structure and binding energy. Comparison with quantum-mechanical calculations will allow us to fully understand the systems and to put confidence bars in our computational models. This is a delicate and essential process to refine the computational models, which are later used to simulate basic processes as protein-receptor interactions.