title: Ultrafast Electronic Relaxation through a Conical Intersection: Nonadiabatic Dynamics Disentangled through an Oscillator Strength-Based Diabatization Framework.
abstract: We employ surface hopping trajectories to model the short-time dynamics of gas-phase and partially solvated 4-(N,N-dimethylamino)benzonitrile (DMABN), a dual fluorescent molecule that is known to undergo a nonadiabatic transition through a conical intersection. To compare theory vs time-resolved fluorescence measurements, we calculate the mixed quantum-classical density matrix and the ensemble averaged transition dipole moment. We introduce a diabatization scheme based on the oscillator strength to convert the TDDFT adiabatic states into diabatic states of Laand Lbcharacter. Somewhat surprisingly, we find that the rate of relaxation reported by emission to the ground state is almost 50% slower than the adiabatic population relaxation. Although our calculated adiabatic rates are largely consistent with previous theoretical calculations and no obvious effects of decoherence are seen, the diabatization procedure introduced here enables an explicit picture of dynamics in the branching plane, raising tantalizing questions about geometric phase effects in systems with dozens of atoms.
authors.affiliation: Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Gregory R
authors.identifier: http://orcid.org/0000-0001-8988-4401
authors.initials: GR
authors.lastname: Medders
authors.affiliation: Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ethan C
authors.initials: EC
authors.lastname: Alguire
authors.affiliation: Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Amber
authors.initials: A
authors.lastname: Jain
authors.affiliation: Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.|Stanford PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Subotnik