First-principles G₀W₀ calculations for ferrocene, anthracene and porphyrin

Hedin's GW approximation is well-known as a powerful method in the material science community because of its high quality and relatively low computational cost. In this study, we evaluate the performance of the G₀W₀ approximation for the charged quasi-particle excitation energies of three gas-phase molecules of interest for organic electronics, including ferrocene, porphyrin and anthracene. Moreover, we assess the undesired starting-point dependence in this method by benchmarking the ionization energies obtained from G₀W₀ on top of the spin-resolved Hartree-Fock and Kohn-Sham methods. The merit of dynamic effective GW self-energy leads to significant improvement of ionization energies compared to mean-field calculations and deviations less than 0.4 eV as compared to experiment. The calculations are carried out by the use of numerical atomic orbitals and contour deformation technique along with an iterative procedure to deal with the energy dependency of GW self-energy and full matrix elements of the dynamically screened Coulomb interaction.