We study within the perturbative many-body GW and Bethe-Salpeter approach the low lying singlet charge-transfer excitations in molecular donor-acceptor complexes associating benzene, naphtalene and anthracene derivatives with the tetracyanoethylene acceptor. Our calculations demonstrate that such techniques can reproduce the experimental data with a mean average error of 0.1-0.15 eV for the present set of dimers, in excellent agreement with the best time-dependent density functional studies with optimized range-separated functionals. The present results pave the way to the study of photoinduced charge transfer processes in photovoltaic devices with a parameter-free \textit{ab initio} approach showing equivalent accuracy for finite and extended systems.
@article{arxiv.1109.0824,
title = {Charge-transfer excitations in molecular donor-acceptor complexes within the many-body Bethe-Salpeter approach},
author = {X. Blase and C. Attaccalite},
journal= {arXiv preprint arXiv:1109.0824},
year = {2015}
}