In our approach, intermolecular interactions are defined based on specific geometrical criteria (detailed information on the selection of the criteria used to determine the noncovalent interactions in the system is provided in Section A of the SI). Two phenol molecules are considered to form a hydrogen bond when the O H distance is less than 2.6 Å and the O H O angle is between 135 and 180 • . The π-electronic clouds of two phenyl groups are considered to interact when the distance between the centers of mass of the carbon atoms in each molecule is less than 4.0 Å. C H O interactions are present if the H O distance is lower than 2.8 Å and the angle with the adjacent C atom is between 120 and 180 • . Finally, X H π interactions are defined when the H π distance is lower than 3.0 Å with a C H π or O H π angle in the range of 120 • to 180 • or 135 • to 180 • , respectively. The effect on the populations of using different thresholds has been proven to be rather limited, as shown in the SI (Section D), which supports the robustness of our approach. This protocol can be applied to the snapshots generated through MD simulations, which may include all or just part of the interaction patterns. The total population would be given by the average over all snapshots, which would generally include all interaction patterns for sufficiently long trajectories. The same protocol can be applied to an ensemble of configurations generated through a systematic conformational search. In this case, the number of interaction patterns identified will depend on the extent of the automated search. All algorithms described here have been implemented in Aggregate 72 , a code developed by one of us to identify and classify interaction patterns.