DFT-based Green's function pathways model for prediction of bridge-mediated electronic coupling

Abstract

A density functional theory-based Green's function pathway model is developed enabling further advancements towards the long-standing challenge of accurate yet inexpensive prediction of electron transfer rate. Electronic coupling predictions are demonstrated to within 0.1 eV of experiment for organic and biological systems of moderately large size, with modest computational expense. Benchmarking and comparisons are made across density functional type, basis set extent, and orbital localization scheme. The resulting framework is shown to be flexible and to offer quantitative prediction of both electronic coupling and tunneling pathways in covalently bound non-adiabatic donor-bridge-acceptor (D-B-A) systems. A new localized molecular orbital Green's function pathway method (LMO-GFM) adaptation enables intuitive understanding of electron tunneling in terms of through-bond and through-space interactions.

Spin-Polarization-Induced Preedge Transitions in the Sulfur K-Edge XAS Spectra of Open-Shell Transition-Metal Sulfates: Spectroscopic Validation of σ-Bond Electron Transfer

“…75–77 This study thus reports the first direct spectroscopic confirmation of the theory of σ-bond conduction pathways critically central to electron transfer in metalloproteins and enzymes. 69, 72, 76, 77 …”

Electronic Coupling Calculations for Bridge-Mediated Charge Transfer Using Constrained Density Functional Theory (CDFT) and Effective Hamiltonian Approaches at the Density Functional Theory (DFT) and Fragment-Orbital Density Functional Tight Binding (FODFTB) Level

“…The optimal accuracy of this localization scheme within this approach was demonstrated in previous works. 71 In FODFTB calculations, we apply fragment orbitals as localized states, which are straightforward to use when D, A and B are separated molecules. 51 By solving one linear equation for !…”

“…Applying the respective optimized parameter for each approach (see previous section and ref 71 71 This methodology therefore was demonstrated to be highly sensitive to the localization method in order to achieve predictions comparable to experiment. For all molecules, calculations at DFBT2 level give the lowest electronic coupling and T DA for molecule 7…”

“…Hamiltonian strategy with DFT-based Green's function pathway. 45 Electronic coupling contributions to ET through diverse biomolecules, including DNA strands, 46-49 polypeptide [50][51][52][53] , heme-to-heme ET 54 or cryptochrome/photolyases, 55,56 and to organic semi-conductors 57 have been successfully calculated with these approaches. In addition to our recent works, Ando and co-workers demonstrate the utility of the fragment molecular orbital-linear combination of MOs (FMO-LCMO) for T DA predictions within various organic and biological molecules.…”

Rational design of doubly-bridged chromophores for singlet fission and triplet–triplet annihilation

“…This might be due to distortion of the p-plane in the chromophores, and also be related to the sensitivity to the localization method used to evaluate the couplings in the previous study. 98 Enormous contributions in F LL other than direct and p-orbital bridge-mediated terms is partly due to non-negligible interactions with s-orbitals of bridges (see ESI †). To resolve this strange behaviour for such a kind of compounds, we might need further development of the present theory, which is le for the future investigation.…”