Applications of a dominant product basis in many-body perturbation theory

The knowledge of excitation properties of molecules is crucial in developing organic semiconductor devices. Many-body perturbation theory is one of the most promising theories for characterization of excitations in electronic systems. In particular, Hedin's GW approximation for one-electron Green's function is capable of calculating lumo and homo of molecules with O(N3) computational complexity like TDDFT (see the contribution of Dietrich Foerster). In this work, we implement the Hedin's G0 W0 approximation on top of DFT calculations performed with SIESTA code. We apply a dominant product technique to span the space of orbital products and to reduce the dimensionality of dielectric matrix. We discuss several results for ionization potentials and electron affinities of large molecules, revealing strengths and limitations of our implementation.