Quantum interference (QI) effects have been invoked as an important mechanism to control charge/spin transport properties in molecular electronics. For conduction pathways connected by alternant hydrocarbons, subtle variations in bond connectivity can impact conditions that lead to constructive or destructive quantum interference (CQI and DQI, respectively). The classic example involves comparing transport between 1,3-phenylene (13Ph) and 1,4-phenylene (14Ph) bridges, where the conductance of the 13Ph bridge is decreased by several orders of magnitude due to DQI. Graphical models have been established to predict molecular bridges that yield DQI and CQI as they pertain to phase-coherent charge transport through frontier molecular orbitals (FMOs) in conjugated systems. This method involves drawing a continuous path from one connection point to the other, and pairing up atoms in the alternate path. If there is an odd number of atoms in the alternate path such that not all atoms are part of a pair, DQI is expected (Figure ). A similar set of principles have been applied to biradical systems (Ovchinnikov's rule and related theorems) and used to predict the relative stabilities of the open-shell singlet and triplet states. The applicability of graphical QI models as a predictive tool for photoexcited (excitonic) processes in donor-bridge-acceptor (DBA) chromophores is less established. A key difference is that photoexcited charge transfer involves specific orbitals on donor and acceptor sites that may exhibit different symmetries compared to those involved in conductance measurements. For example, Grozema and coworkers studied photoinduced electron and hole transfer in DBA chromophores. They found that QI could not be readily predicted from the connectivity of the bridge alone. To explain differences in charge transfer rates for different bridge connectivity, it was necessary to also account for symmetry relations of the donor, bridge, and acceptor. These important fundamental results highlight the additional complexity inherent in describing dynamical photoexcited processes, which includes identifying key molecular orbitals and quantifying their character, relative energy, symmetries, and coupling strength. Computational modeling is thus essential to characterize QI effects in DBAs and other excited state systems.