Ultrafast exciton delocalization and localization dynamics of a perylene bisimide quadruple π-stack: a nonadiabatic dynamics simulation

Abstract

Unraveling the photogenerated exciton dynamics of π­stacked molecular aggregates is of great importance for both fundamental studies and industrial applications. Among various π­stacked molecular aggregates, perylene tetracarboxylic acid bisimides (PBI)...

Exciton Localization and Transfer in Azobenzene Aggregates: A Surface Hopping Molecular Dynamics Study

“…With this aim, we perform nonadiabatic, surface hopping molecular dynamics simulations for QM tetramer models (with and without additional steric constraint of surrounding MM molecules; and for short and longer intermolecular separation distances) to reveal the fate of the excitons after photoexcitation. We explore the exciton dynamics using a transition density matrix analysis, allowing one to judge on spatial localization of excitons during dynamics. − In the present study, we treat the electronic subsystem of the tetramers fully quantum mechanically (albeit on a semiempirical level described in the next section), without resorting to more approximate descriptions, such as exciton models.…”

Surface hopping modeling of charge and energy transfer in active environments

“…Large systems, like those including the environment, may be especially prone to this problem, which can be addressed with different techniques. 6,[35][36][37] In general, conventional surface hopping will perform well if (1) the light pulse is shorter than the excited-state dynamics, (2) the nuclei move fast like quasi-classical particles, (3) there are no significant recoherences between nuclear wave packets, and (4) non-local effects can be neglected. However, even if these conditions are not satisfied, specific surface hopping implementations may be available to extend its validity domain, for instance, including fast nuclear degrees of freedom in the quantum partition 38 or explicitly accounting for the electromagnetic field in the Hamiltonian.…”

“…Large systems, like those including the environment, may be especially prone to this problem, which can be addressed with different techniques. 6,35–37…”

Surface hopping modeling of charge and energy transfer in complex environments

“…Large systems, like those including the environment, may be especially prone to this problem, which can be addressed with different techniques. 6,33,34 In general, conventional surface hopping will perform well if 1) the light pulse is shorter than the excited-state dynamics, 2) the nuclei move fast like quasi-classical particles, 3) there are no significant recoherences between nuclear wave packets, and 4) non-local effects can be neglected. However, even if these conditions are not satisfied, specific surface hopping implementations may be available to extend its validity domain, for instance, including fast nuclear degrees of freedom in the quantum partition 35 or explicitly accounting for the electromagnetic field in the Hamiltonian.…”