When a screen is uploaded to Autoparty, the LUNA toolkit calculates intermolecular interactions between all input molecules and the protein structure. This process comprises two steps: First, the biochemical properties of the ligand and protein atoms at the interface are determined using openbabel or RDKit. This includes the determination of atomic groups, such as aromatic rings, that participate as a single interacting group. Groups are visualized in Autoparty as white spheres at the group's center of mass. Second, interactions are defined as pairs of atoms or atomic groups in proximity that meet certain geometric and chemical criteria.