A simple combination of DFT/TDDFT and configuration interaction is presented to fix up the incorrect topology of the S0-S1 conical intersection (CI) and allow a description of bond making and bond breaking in photo-induced dynamics. The proposed TDDFT-1D method includes one lone optimized doubly excited configuration in addition to the DFT/TDDFT singly-excited states within the context of a large configuration interaction Hamiltonian. Results for ethylene and stilbene are provided to demonstrate that this ansatz can yield physically meaningful potential energy surfaces near S0-S1 avoided crossings, without changing the vertical excitation energies far from the relevant crossings. We also investigate the famous linear water example to show that the algorithm calculates the correct topology of the S0-S1 CI and yields the correct geometric phase.

Simplest possible approach for simulating S0-S1 conical intersections with DFT/TDDFT: Adding One doubly excited configuration

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.