Cavity Quantum Electrodynamical Time-Dependent Density Functional Theory Modeling of Molecules Embedded in Optical Cavity

Microcavity engineering has provided a novel approach for tuning molecular optical properties and chemical reactivities through collective strong couplings of an ensemble of molecules inside the cavity. Here, we would introduce a hierarchy of cavity quantum electrodynamical time-dependent density functional theory (cQED-TDDFT) models implemented with Gaussian basis set to capture the exciton polariton states, beyond the few-state approximations. Then we present the extension of the models to an ensemble of many non-interacting (or weakly-interacting) molecules coupled to the photon modes for a more realistic condition. Various effects are systematically examined, including geometry fluctuations, non-uniform orientations, and intermolecular interactions, on the bright polariton states and the dense dark states.