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arXiv · 2312.07123

Triplet Excitation-Energy Transfer Couplings from Subsystem Time-Dependent Density-Functional Theory

Sabine Käfer·Niklas Niemeyer·Johannes Tölle·Johannes Neugebauer
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Abstract

We present an implementation of Triplet Excitation-Energy Transfer (TEET) couplings based on subsystem-based Time-Dependent Density-Functional Theory (sTDDFT). TEET couplings are systematically investigated by comparing "exact" and approximate variants of sTDDFT. We demonstrate that, while sTDDFT utilizing explicit approximate Non-Additive Kinetic Energy (NAKE) density functionals is well-suited for describing Singlet Excitation-Energy Transfer (SEET) processes, it is inadequate for characterizing TEET. However, we show that Projection-based Embedding (PbE)-based sTDDFT addresses the challenges faced by NAKE-sTDDFT and emerges as a promising method for accurately describing electronic couplings in TEET processes. We also introduce the mixed PbE-/NAKE-embedding procedure to investigate TEET effects in solvated pairs of chromophores. This approach offers a good balance between accuracy and efficiency, enabling comprehensive studies of TEET processes in complex environments.

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Sabine Käfer, Niklas Niemeyer, Johannes Tölle, Johannes Neugebauer. 2023-12-12. Triplet Excitation-Energy Transfer Couplings from Subsystem Time-Dependent Density-Functional Theory. https://arxiv.org/abs/2312.07123

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