Abstract
<jats:p>Electronic coupling (charge transfer integral) between monomeric units is a critical parameter that dictates the rate and mode of charge transport in organic systems. Its accurate determination requires the use of a suitable level of theory for electronic interactions and an appropriate diabatization scheme to extract the coupling parameters from adiabatic states. Here we show that this objective can be achieved using the static Coulombhole screened-exchange (st-COHSEX) method within a generalized Mulliken-Hush (GMH) scheme tailored for Koopmans-like one-particle theories. The st-COHSEX method, a parameter-free effective potential approach that includes long-range electron-electron correlation, is shown to provide consistently reliable intramolecular hole-transfer couplings for the donor-bridge-acceptor (DBA) dataset, and intermolecular electron-and holetransfer couplings and their decay constants for the HAB79 dataset. Accuracy of st-COHSEX is notably high for electron coupling, yielding a mean-unsigned error (MUE) of 7.0 meV and mean-relative unsigned error (MRUE) of 13.6% against NEVPT2 benchmark values. For hole-transfer couplings, the st-COHSEX method has a MUE of 9.1 meV and MRUE of 19.9 %, which is comparable to hybrid functionals. The errors are shown to reduce when using many-body methods like GKS-spRPA and G0W0. Given its computational efficiency, the st-COHSEX method is a parameter-free alternative to hybrid functionals for the rapid modeling of electronic couplings. It can also serve as a benchmark method for the case of electron-transfer couplings.</jats:p>