Intermolecular\nInteractions and Quantum Interference\nEffects in Molecular Junctions

Destructive quantum interference (DQI) leads to a decrease\nin the\nconductance of certain well-documented molecules. Experimental observations\nhave revealed both direct and indirect manifestations of DQI, although\na comprehensive understanding of the underlying causes of these distinct\noutcomes remains elusive. In both cases, DQI lowers the conductance,\nbut only the direct case exhibits a characteristic V-shaped dip in\ndifferential conductance. Currently, the direct signature has exclusively\nbeen observed in monolayers and gated single-molecule systems. In\nthis study, we employ density functional theory to elucidate a plausible\nexplanation for the absence of a direct DQI signature in single molecules.\nSpecifically, we attribute the direct DQI signature to a resonance\nshift induced by intermolecular interactions, which are absent in\nthe individual molecules. By illustrating the impact of these intermolecular\ninteractions, we emphasize the need for explicit treatment of intermolecular\ninteractions when simulating monolayers.