First-principles GW calculations for DNA and RNA nucleobases

TL;DR

This study applies first-principles GW calculations to DNA and RNA nucleobases, accurately predicting ionization energies and electron affinities, and clarifies their electronic structure with a new computational approach.

Contribution

It introduces a simple self-consistent GW method starting from Kohn-Sham states, improving accuracy in quasiparticle property predictions for nucleobases.

Findings

Vertical ionization energies within 0.11 eV of advanced methods

Electron affinities within 0.18 eV of benchmark approaches

Correct c -character of highest occupied state predicted

Abstract

On the basis of first-principles GW calculations, we study the quasiparticle properties of the guanine, adenine, cytosine, thymine, and uracil DNA and RNA nucleobases. Beyond standard G0W0 calculations, starting from Kohn-Sham eigenstates obtained with (semi)local functionals, a simple self-consistency on the eigenvalues allows to obtain vertical ionization energies and electron affinities within an average 0.11 eV and 0.18 eV error respectively as compared to state-of-the-art coupled-cluster and multi-configurational perturbative quantum chemistry approaches. Further, GW calculations predict the correct \pi -character of the highest occupied state, thanks to several level crossings between density functional and GW calculations. Our study is based on a recent gaussian-basis implementation of GW with explicit treatment of dynamical screening through contour deformation techniques.