Quantitative Molecular Orbital Energies within a $G_0{W}_0$ Approximation

Abstract

Using many-body perturbation theory within the $G_0{W}_0$ approximation, we explore routes for computing the ionization potential (IP), electron affinity (EA), and fundamental gap of three gas-phase molecules -- benzene, thiophene, and (1,4) diamino-benzene -- and compare with experiments. We examine the dependence of the IP on the number of unoccupied states used to build the dielectric function and the self energy, as well as the dielectric function plane-wave cutoff. We find that with an effective completion strategy for approximating the unoccupied subspace, and a converged dielectric function kinetic energy cutoff, the computed IPs and EAs are in excellent quantitative agreement with available experiment (within 0.2 eV), indicating that a one-shot $G_0{W}_0$ approach can be very accurate for calculating addition/removal energies of small organic molecules. Our results indicate that a sufficient dielectric function kinetic energy cutoff may be the limiting step for a wide application of $G_0{W}_0$ to larger organic systems.

References in corpus (4)

• First-principles GW calculations for fullerenes, porphyrins, phtalocyanine, and other molecules of interest for organic photovoltaic applications
• Ab initio GW many-body effects in graphene
• Quasiparticle and Optical Properties of Rutile and Anatase TiO${}_2$
• Enhanced Static Approximation to the Electron Self-Energy Operator for Efficient Calculation of Quasiparticle Energies

Cited by in corpus (2)

• A Benchmark of GW Methods for Azabenzenes: Is the GW Approximation Good Enough?
• Accurate ionization potential of gold anionic clusters from density functional theory and many-body perturbation theory