Our principal methodological direction is the development of effective one-electron potential and transfer-integral (EOP-TI) models for excitation energy transfer between chromophores. The aim is to retain the physically relevant contributions to the coupling while reducing the cost of evaluating an excitonic Hamiltonian for molecular aggregates.
The published EOP-TI formulation combines effective one-electron potentials with a transfer-integral description that includes charge-transfer configurations. It was tested at fragment separations where overlap-dependent contributions become important. The accuracy depends on the approximations used for the underlying electronic states (Błasiak et al., 2021).
This work builds on our treatment of charge-transfer interactions with effective potentials (Błasiak et al., 2021) and on distributed multipole models of the Coulombic contribution to excitation energy transfer (Błasiak et al., 2015). These are complementary parts of the description, with different roles at different fragment separations.
Current direction
Further development and assessment of EOP-TI is the main focus of our current research. We are interested in how the electronic structure of the fragments and their relative arrangement determine the coupling, and in computational protocols that can connect this molecular description with applications in photochemistry.
Selected publications
- Błasiak et al. An effective potential for Frenkel excitons. Physical Chemistry Chemical Physics 2021, 23, 1923–1935.
- Błasiak et al. Ab initio effective one-electron potential operators: Applications for charge-transfer energy in effective fragment potentials. Journal of Computational Chemistry 2021, 42, 398–411.
- Błasiak et al. Distributed Multipolar Expansion Approach to Calculation of Excitation Energy Transfer Couplings. Journal of Chemical Theory and Computation 2015, 11, 3259–3266.