  The photoelectron properties of DNA and RNA bases are studied using many-body
perturbation theory within the GW approximation, together with a recently
developed Lanczos-chain approach. Calculated vertical ionization potentials,
electron affinities, and total density of states are in good agreement with
experimental values and photoemission spectra. The convergence benchmark
demonstrates the importance of using an optimal polarizability basis in the GW
calculations. A detailed analysis of the role of exchange and correlation in
both many-body and density-functional theory calculations shows that while
self-energy corrections are strongly orbital-dependent, they nevertheless
remain almost constant for states that share the same bonding character.
Finally, we report on the inverse lifetimes of DNA and RNA bases, that are
found to depend linearly on quasi-particle energies for all deep valence
states. In general, our G0W0-Lanczos approach provides an efficient yet
accurate and fully converged description of quasiparticle properties of five
DNA and RNA bases.
